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	Author	Zha, G.-Q.; Peeters, F.M.; Zhou, S.-P.
	Title	Vortex-antivortex dynamics in mesoscopic symmetric and asymmetric superconducting loops with an applied ac current			Type	A1 Journal article
	Year	2014	Publication	Europhysics letters	Abbreviated Journal	Epl-Europhys Lett
	Volume	108	Issue	5	Pages	57001
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	In the framework of the time-dependent Ginzburg-Landau formalism, we study the dynamics of vortex-antivortex (V-Av) pairs in mesoscopic symmetric and asymmetric superconducting loops under an applied ac current. In contrast to the case of a constant biasing dc current, the process of the V-Av collision and annihilation is strongly affected by the time-periodic ac signal. As the direction of the applied ac current is reversed, the existed V-Av pair moves backward and then collides with a new created Av-V pair in a symmetric loop. In the presence of an appropriate external magnetic field, a novel sinusoidal-like oscillatory mode of the magnetization curve is observed, and the periodic dynamical process of the V-Av annihilation occurs in both branches of the sample. Moreover, for the asymmetric sample with an off-centered hole the creation point of the V-Av pair shifts away from the center of the sample, and the creation and annihilation dynamics of V-Av pairs turns out to be very different from the symmetric case. Copyright (C) EPLA, 2014
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Paris	Editor
	Language		Wos	000346792400027	Publication Date	2014-11-28
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0295-5075;1286-4854;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.957	Times cited	4	Open Access
	Notes	; We are grateful to GOLIBJON BERDIYOROV for useful discussions. This work was supported by NSF China under Grant Nos. 61371020 and 61271163, by Visiting Scholar Program of Shanghai Municipal Education Commission, by Innovation Program of Shanghai Municipal Education Commission under Grant No. 13YZ006, and by Flemish Science Foundation (FWO-Vl). ;			Approved	Most recent IF: 1.957; 2014 IF: 2.095
	Call Number	UA @ lucian @ c:irua:122800			Serial	3851
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	Author	Xu, B.; Milošević, M.V.; Peeters, F.M.
	Title	Calorimetric properties of mesoscopic superconducting disks, rings, and cylinders			Type	A1 Journal article
	Year	2010	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
	Volume	81	Issue	6	Pages	064501,1-064501,10
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The thermal signatures of superconductivity in mesoscopic disks, rings and cylinders are calculated within the Ginzburg-Landau theory. In an applied perpendicular magnetic field H the heat capacity of mesoscopic samples shows a strong dependence on the realized vortex state; discontinuities are found at the critical field for different vorticities, as well as at the superconducting-to-normal state transition. The same applies to the intermediate state of type-I superconductors. Even the subtle changes in the fluxoid distribution inside the sample leave clear signatures on heat capacity, which is particularly useful for fully three-dimensional samples whose interior is often inaccessible by magnetometry. The heat-capacity jump ΔC(H) at the critical temperature exhibits quasiperiodic modulations as a function of magnetic field. In mesoscopic superconducting rings, these oscillations provide calorimetric verification of the Little-Parks effect.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000274998100091	Publication Date	2010-02-01
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	17	Open Access
	Notes	; We are grateful to O. Bourgeois for useful discussions. This work was supported by the Flemish Science Foundation (FWO-VI), the Interuniversity Attraction Poles (IAP) Program-Belgian State-Belgian Science Policy, ESF-JSPS NES program and the ESF-AQDJJ network. ;			Approved	Most recent IF: 3.836; 2010 IF: 3.774
	Call Number	UA @ lucian @ c:irua:81766			Serial	271
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	Author	Peelaers, H.; Partoens, B.; Giantomassi, M.; Rangel, T.; Goossens, E.; Rignanese, G.-M.; Gonze, X.; Peeters, F.M.
	Title	Convergence of quasiparticle band structures of Si and Ge nanowires in the GW approximation and the validity of scissor shifts			Type	A1 Journal article
	Year	2011	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
	Volume	83	Issue	4	Pages	045306-045306,6
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Starting from fully converged density-functional theory calculations, the quasiparticle corrections are calculated for different sized Si and Ge nanowires using the GW approximation. The effectiveness of recently developed techniques in speeding up the convergence of the quasiparticle calculations is demonstrated. The complete quasiparticle band structures are also obtained using an interpolation technique based on maximallylocalized Wannier functions. From the quasiparticle results, we assess the correctness of the commonly applied scissor-shift correction. Dispersion changes are observed, which are also reflected in changes in the effective band masses calculated taking into account quasiparticle corrections.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000286771400004	Publication Date	2011-01-21
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	18	Open Access
	Notes	; We are grateful to Yann Pouillon for valuable technical support with the build system of ABINIT, related to the WANNIER90 library. This work was supported by the Flemish Science Foundation (FWO-Vl) and by the Interuniversity Attraction Poles Program (P6/42)-Belgian State-Belgian Science Policy. X. G. and G.-M. R. acknowledge funding from the EU's 7th Framework Programme through the ETSF I3 e-Infrastructure project (Grant No. 211956), the Communaute francaise de Belgique through the Action de Recherche Concertee 07/12-003 “Nanosystemes hybrides metal-organiques,” and the Wallon Region Project No. 816849 “ European Theoretical Spectroscopy Facility” (WALL ETSF). M. G. acknowledges funding from the FRFC Project No. 2.4.589.09.F. ;			Approved	Most recent IF: 3.836; 2011 IF: 3.691
	Call Number	UA @ lucian @ c:irua:86905			Serial	510
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	Author	Neek-Amal, M.; Peeters, F.M.
	Title	Nanoindentation of a circular sheet of bilayer graphene			Type	A1 Journal article
	Year	2010	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
	Volume	81	Issue	23	Pages	235421,1-235421,6
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Nanoindentation of bilayer graphene is studied using molecular-dynamics simulations. We compared our simulation results with those from elasticity theory as based on the nonlinear Föppl-Hencky equations with rigid boundary condition. The force-deflection values of bilayer graphene are compared to those of monolayer graphene. Youngs modulus of bilayer graphene is estimated to be 0.8 TPa which is close to the value for graphite. Moreover, an almost flat bilayer membrane at low temperature under central load has a 14% smaller Youngs modulus as compared to the one at room temperature.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000278710800003	Publication Date	2010-06-11
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	108	Open Access
	Notes	; We gratefully acknowledge comments from R. Asgari. M.N.-A. would like to thank the Universiteit of Antwerpen for its hospitality where part of this work was performed. This work was supported by the Flemish science foundation (FWO-V1) and the Belgium Science Policy (IAP). ;			Approved	Most recent IF: 3.836; 2010 IF: 3.774
	Call Number	UA @ lucian @ c:irua:83093			Serial	2259
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	Author	Mirzakhani, M.; Peeters, F.M.; Zarenia, M.
	Title	Circular quantum dots in twisted bilayer graphene			Type	A1 Journal article
	Year	2020	Publication	Physical Review B	Abbreviated Journal	Phys Rev B
	Volume	101	Issue	7	Pages	075413
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Within a tight-binding approach, we investigate the effect of twisting angle on the energy levels of circular bilayer graphene (BLG) quantum dots (QDs) in both the absence and presence of a perpendicular magnetic field. The QDs are defined by an infinite-mass potential, so that the specific edge effects are not present. In the absence of magnetic field (or when the magnetic length is larger than the moire length), we show that the low-energy states in twisted BLG QDs are completely affected by the formation of moire patterns, with a strong localization at AA-stacked regions. When magnetic field increases, the energy gap of an untwisted BLG QD closes with the edge states, localized at the boundaries between the AA- and AB-stacked spots in a twisted BLG QD. Our observation of the spatial localization of the electrons in twisted BLG QDs can be experimentally probed by low-bias scanning tunneling microscopy measurements.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000512772200004	Publication Date	2020-02-13
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2469-9969; 2469-9950	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.7	Times cited	13	Open Access
	Notes	; We gratefully acknowledge discussions with I. Snyman. M.Z. acknowledges support from the U.S. Department of Energy (Office of Science) under Grant No. DE-FG0205ER46203. ;			Approved	Most recent IF: 3.7; 2020 IF: 3.836
	Call Number	UA @ admin @ c:irua:166493			Serial	6470
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	Author	Costamagna, S.; Neek-Amal, M.; Los, J.H.; Peeters, F.M.
	Title	Thermal rippling behavior of graphane			Type	A1 Journal article
	Year	2012	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
	Volume	86	Issue	4	Pages	041408-4
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Thermal fluctuations of single layer hydrogenated graphene (graphane) are investigated using large scale atomistic simulations. By analyzing the mean square value of the height fluctuations < h(2)> and the height-height correlation function H(q) for different system sizes and temperatures, we show that hydrogenated graphene is an unrippled system in contrast to graphene. The height fluctuations are bounded, which is confirmed by a H(q) tending to a constant in the long wavelength limit instead of showing the characteristic scaling law q(4-eta)(eta similar or equal to 0.85) predicted by membrane theory. This unexpected behavior persists up to temperatures of at least 900 K and is a consequence of the fact that in graphane the thermal energy can be accommodated by in-plane bending modes, i.e., modes involving C-C-C bond angles in the buckled carbon layer, instead of leading to significant out-of-plane fluctuations that occur in graphene.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Lancaster, Pa	Editor
	Language		Wos	000306649200002	Publication Date	2012-07-23
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	46	Open Access
	Notes	; We thank A. Fasolino, A. Dobry, and K. H. Michel for their useful comments. S.C. is supported by the Belgian Science Foundation (BELSPO). This work is supported by the ESF-EuroGRAPHENE project CONGRAN and the Flemish Science Foundation (FWO-Vl). ;			Approved	Most recent IF: 3.836; 2012 IF: 3.767
	Call Number	UA @ lucian @ c:irua:100840			Serial	3630
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	Author	Neek-Amal, M.; Beheshtian, J.; Shayeganfar, F.; Singh, S.K.; Los, J.H.; Peeters, F.M.
	Title	Spiral graphone and one-sided fluorographene nanoribbons			Type	A1 Journal article
	Year	2013	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
	Volume	87	Issue	7	Pages	075448-8
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The instability of a free-standing one-sided hydrogenated/fluorinated graphene nanoribbon, i.e., graphone/fluorographene, is studied using ab initio, semiempirical, and large-scale molecular dynamics simulations. Free-standing semi-infinite armchairlike hydrogenated/fluorinated graphene (AC-GH/AC-GF) and boatlike hydrogenated/fluorinated graphene (B-GH/B-GF) (nanoribbons which are periodic along the zigzag direction) are unstable and spontaneously transform into spiral structures. We find that rolled, spiral B-GH and B-GF are energetically more favorable than spiral AC-GH and AC-GF which is opposite to the double-sided flat hydrogenated/fluorinated graphene, i.e., graphane/fluorographene. We found that the packed, spiral structures exhibit an unexpected localized highest occupied molecular orbital and lowest occupied molecular orbital at the edges with increasing energy gap during rolling. These rolled hydrocarbon structures are stable beyond room temperature up to at least T = 1000 K within our simulation time of 1 ns. DOI: 10.1103/PhysRevB.87.075448
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000315481800005	Publication Date	2013-02-27
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	14	Open Access
	Notes	; We thank A. Sadeghi, M. R. Ejtehadi, and J. Amini for their useful comments. This work is supported by the ESF EuroGRAPHENE project CONGRAN and the Flemish Science Foundation (FWO-Vl). M.N.-A. is supported by a EU-Marie Curie IIF fellowship program Grant No. 299855. ;			Approved	Most recent IF: 3.836; 2013 IF: 3.664
	Call Number	UA @ lucian @ c:irua:107654			Serial	3106
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	Author	Zarenia, M.; Neilson, D.; Peeters, F.M.
	Title	Inhomogeneous phases in coupled electron-hole bilayer graphene sheets : charge density waves and coupled wigner crystals			Type	A1 Journal article
	Year	2017	Publication	Scientific reports	Abbreviated Journal	Sci Rep-Uk
	Volume	7	Issue		Pages	11510
	Keywords	A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
	Abstract	Recently proposed accurate correlation energies are used to determine the phase diagram of strongly coupled electron-hole graphene bilayers. The control parameters of the phase diagram are the charge carrier density and the insulating barrier thickness separating the bilayers. In addition to the electron-hole superfluid phase we find two new inhomogeneous ground states, a one dimensional charge density wave phase and a coupled electron-hole Wigner crystal. The elementary crystal structure of bilayer graphene plays no role in generating these new quantum phases, which are completely determined by the electrons and holes interacting through the Coulomb interaction. The experimental parameters for the new phases lie within attainable ranges and therefore coupled electron-hole bilayer graphene presents itself as an experimental system where novel emergent many-body phases can be realized.
	Address
	Corporate Author				Thesis
	Publisher	Nature Publishing Group	Place of Publication	London	Editor
	Language		Wos	000410739000008	Publication Date	2017-09-11
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2045-2322	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	4.259	Times cited	13	Open Access
	Notes	; We thank Alex Hamilton, Bart Partoens, and Andrea Perali for useful discussions. This work was partially supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem program of the Flemish government. D.N. acknowledges support by the University of Camerino FAR project CESEMN. ;			Approved	Most recent IF: 4.259
	Call Number	UA @ lucian @ c:irua:145620			Serial	4742
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	Author	Michel, K.H.; Costamagna; Peeters, F.M.
	Title	Theory of thermal expansion in 2D crystals			Type	A1 Journal article
	Year	2015	Publication	Physica status solidi: B: basic research	Abbreviated Journal	Phys Status Solidi B
	Volume	252	Issue	252	Pages	2433-2437
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The thermal expansion alpha(T) in layered crystals is of fundamental and technological interest. As suggested by I. M. Lifshitz in 1952, in thin solid films (crystalline membranes) a negative contribution to alpha(T) is due to anharmonic couplings between in-plane stretching modes and out-of-plane bending (flexural modes). Genuine in-plane anharmonicities give a positive contribution to alpha(T). The competition between these two effects can lead to a change of sign (crossover) from a negative value of alpha(T) in a temperature (T) range T <= T-alpha to a positive value of alpha(T) for T > T-alpha in layered crystals. Here, we present an analytical lattice dynamical theory of these phenomena for a two-dimensional (2D) hexagonal crystal. We start from a Hamiltonian that comprises anharmonic terms of third and fourth order in the lattice displacements. The in-plane and out-of-plane contributions to the thermal expansion are studied as functions of T for crystals of different sizes. Besides, renormalization of the flexural mode frequencies plays a crucial role in determining the crossover temperature T-alpha. Numerical examples are given for graphene where the anharmonic couplings are determined from experiments. The theory is applicable to other layer crystals wherever the anharmonic couplings are known. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Berlin	Editor
	Language		Wos	000364690400014	Publication Date	2015-08-06
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0370-1972	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.674	Times cited	21	Open Access
	Notes	; We thank B. Verberck, D. Lamoen, and A. Dobry for useful comments. We acknowledge funding from the FWO (Belgium)-MINCyT (Argentina) collaborative research project. This work is supported by the Euro GRAPHENE project CONGRAN. ;			Approved	Most recent IF: 1.674; 2015 IF: 1.489
	Call Number	UA @ lucian @ c:irua:130281			Serial	4264
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	Author	Michel, K.H.; Costamagna; Peeters, F.M.
	Title	Theory of anharmonic phonons in two-dimensional crystals			Type	A1 Journal article
	Year	2015	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
	Volume	91	Issue	91	Pages	134302
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Anharmonic effects in an atomic monolayer thin crystal with honeycomb lattice structure are investigated by analytical and numerical lattice dynamical methods. Starting from a semiempirical model for anharmonic couplings of third and fourth orders, we study the in-plane and out-of-plane (flexural) mode components of the generalized wave vector dependent Gruneisen parameters, the thermal tension and the thermal expansion coefficients as a function of temperature and crystal size. From the resonances of the displacement-displacement correlation functions, we obtain the renormalization and decay rate of in-plane and flexural phonons as a function of temperature, wave vector, and crystal size in the classical and in the quantum regime. Quantitative results are presented for graphene. There, we find that the transition temperature T-alpha from negative to positive thermal expansion is lowered with smaller system size. Renormalization of the flexural mode has the opposite effect and leads to values of T-alpha approximate to 300 K for systems of macroscopic size. Extensive numerical analysis throughout the Brillouin zone explores various decay and scattering channels. The relative importance of normal and umklapp processes is investigated. The work is complementary to crystalline membrane theory and computational studies of anharmonic effects in two-dimensional crystals.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Lancaster, Pa	Editor
	Language		Wos	000353031000001	Publication Date	2015-04-17
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121; 1550-235x	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	38	Open Access
	Notes	; We thank B. Verberck, D. Lamoen, and A. Dobry for useful comments. We acknowledge funding from the FWO (Belgium)-MINCyT (Argentina) collaborative research project. This work is supported by the EuroGRAPHENE project CONGRAN. ;			Approved	Most recent IF: 3.836; 2015 IF: 3.736
	Call Number	UA @ lucian @ c:irua:132512			Serial	4263
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	Author	Saberi-Pouya, S.; Zarenia, M.; Perali, A.; Vazifehshenas, T.; Peeters, F.M.
	Title	High-temperature electron-hole superfluidity with strong anisotropic gaps in double phosphorene monolayers			Type	A1 Journal article
	Year	2018	Publication	Physical review B	Abbreviated Journal	Phys Rev B
	Volume	97	Issue	17	Pages	174503
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Excitonic superfluidity in double phosphorene monolayers is investigated using the BCS mean-field equations. Highly anisotropic superfluidity is predicted where we found that the maximum superfluid gap is in the Bose-Einstein condensate (BEC) regime along the armchair direction and in the BCS-BEC crossover regime along the zigzag direction. We estimate the highest Kosterlitz-Thouless transition temperature with maximum value up to similar to 90 K with onset carrier densities as high as 4 x 10(12) cm(-2). This transition temperature is significantly larger than what is found in double electron-hole few-layers graphene. Our results can guide experimental research toward the realization of anisotropic condensate states in electron-hole phosphorene monolayers.
	Address
	Corporate Author				Thesis
	Publisher	American Physical Society	Place of Publication	New York, N.Y	Editor
	Language		Wos	000431986100002	Publication Date	2018-05-02
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2469-9969; 2469-9950	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	17	Open Access
	Notes	; We thank David Neilson for helpful discussions. This work was partially supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem program of the Flemish government and Iran Ministry of Science, Research and Technology. ;			Approved	Most recent IF: 3.836
	Call Number	UA @ lucian @ c:irua:151533UA @ admin @ c:irua:151533			Serial	5028
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	Author	Badalyan, S.M.; Peeters, F.M.
	Title	Electron-phonon bound state in graphene			Type	A1 Journal article
	Year	2012	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
	Volume	85	Issue	20	Pages	205453-205453,5
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The fine structure of the Dirac energy spectrum in graphene induced by electron-optical phonon coupling is investigated in the portion of the spectrum near the phonon emission threshold. The derived new dispersion equation in the immediate neighborhood below the threshold corresponds to an electron-phonon bound state. We find that the singular vertex corrections beyond perturbation theory strongly increase the electron-phonon binding energy scale. The predicted enhancement of the effective electron-phonon coupling can be measured using angle-resolved spectroscopy.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000304649400002	Publication Date	2012-05-30
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	12	Open Access
	Notes	; We thank E. Rashba for the useful discussion and acknowledge support from the Belgian Science Policy (IAP) and BELSPO. ;			Approved	Most recent IF: 3.836; 2012 IF: 3.767
	Call Number	UA @ lucian @ c:irua:98939			Serial	982
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	Author	Moldovan, D.; Masir, M.R.; Peeters, F.M.
	Title	Magnetic field dependence of the atomic collapse state in graphene			Type	A1 Journal article
	Year	2018	Publication	2D materials	Abbreviated Journal	2D Mater
	Volume	5	Issue	1	Pages	015017
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	<script type='text/javascript'>document.write(unpmarked('Quantum electrodynamics predicts that heavy atoms (Z \u003E Z(c) approximate to 170) will undergo the process of atomic collapse where electrons sink into the positron continuum and a new family of so-called collapsing states emerges. The relativistic electrons in graphene exhibit the same physics but at a much lower critical charge (Z(c) approximate to 1) which has made it possible to confirm this phenomenon experimentally. However, there exist conflicting predictions on the effect of a magnetic field on atomic collapse. These theoretical predictions are based on the continuum Dirac-Weyl equation, which does not have an exact analytical solution for the interplay of a supercritical Coulomb potential and the magnetic field. Approximative solutions have been proposed, but because the two effects compete on similar energy scales, the theoretical treatment varies depending on the regime which is being considered. These limitations are overcome here by starting from a tight-binding approach and computing exact numerical results. By avoiding special limit cases, we found a smooth evolution between the different regimes. We predict that the atomic collapse effect persists even after the magnetic field is activated and that the critical charge remains unchanged. We show that the atomic collapse regime is characterized: (1) by a series of Landau level anticrossings and (2) by the absence of root B scaling of the Landau levels with regard to magnetic field strength.'));
	Address
	Corporate Author				Thesis
	Publisher	IOP Publishing	Place of Publication	Bristol	Editor
	Language		Wos	000415015000001	Publication Date	2017-10-26
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2053-1583	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	6.937	Times cited	13	Open Access
	Notes	; We thank Eva Andrei, Jinhai Mao and Yuhang Jiang for insightful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Funding of the Flemish Government. ;			Approved	Most recent IF: 6.937
	Call Number	UA @ lucian @ c:irua:147361UA @ admin @ c:irua:147361			Serial	4884
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	Author	Badalyan, S.M.; Peeters, F.M.
	Title	Effect of nonhomogenous dielectric background on the plasmon modes in graphene double-layer structures at finite temperatures			Type	A1 Journal article
	Year	2012	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
	Volume	85	Issue	19	Pages	195444-195444,6
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We have calculated the plasmon modes in graphene double layer structures at finite temperatures, taking into account the inhomogeneity of the dielectric background of the system. The effective dielectric function is obtained from the solution of the Poisson equation of a three-layer dielectric medium with graphene sheets located at the interfaces, separating the different materials. Due to the momentum dispersion of the effective dielectric function, the intra- and interlayer bare Coulomb interactions in the graphene double layer system acquires an additional momentum dependence-an effect that is of the order of the interlayer interaction itself. We show that the energies of the in-phase and out-of-phase plasmon modes are determined largely by different values of the spatially dependent effective dielectric function. The effect of the dielectric inhomogeneity increases with temperature, and even at high temperatures the energy shift induced by the dielectric inhomogeneity and temperature itself remains larger than the broadening of the plasmon energy dispersions due to the Landau damping. The obtained new features of the plasmon dispersions can be observed in frictional drag measurements and in inelastic light scattering and electron energy-loss spectroscopies.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000304394800011	Publication Date	2012-05-23
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	67	Open Access
	Notes	; We thank G. Vignale for useful discussions and acknowledge support from the Flemisch Science Foundation (FWO-Fl) and the Belgian Science Policy (BELSPO). ;			Approved	Most recent IF: 3.836; 2012 IF: 3.767
	Call Number	UA @ lucian @ c:irua:98941			Serial	826
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	Author	Saberi-Pouya, S.; Conti, S.; Perali, A.; Croxall, A.F.; Hamilton, A.R.; Peeters, F.M.; Neilson, D.
	Title	Experimental conditions for the observation of electron-hole superfluidity in GaAs heterostructures			Type	A1 Journal article
	Year	2020	Publication	Physical Review B	Abbreviated Journal	Phys Rev B
	Volume	101	Issue	14	Pages	140501-140506
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The experimental parameter ranges needed to generate superfluidity in optical and drag experiments in GaAs double quantum wells are determined using a formalism that includes self-consistent screening of the Coulomb pairing interaction in the presence of the superfluid. The very different electron and hole masses in GaAs make this a particularly interesting system for superfluidity with exotic superfluid phases predicted in the BCS-Bose-Einstein condensation crossover regime. We find that the density and temperature ranges for superfluidity cover the range for which optical experiments have observed indications of superfluidity but that existing drag experiments lie outside the superfluid range. We also show that, for samples with low mobility with no macroscopically connected superfluidity, if the superfluidity survives in randomly distributed localized pockets, standard quantum capacitance measurements could detect these pockets.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000523627600001	Publication Date	2020-04-06
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2469-9969; 2469-9950	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.7	Times cited	13	Open Access
	Notes	; We thank K. Das Gupta, F. Dubin, U. Siciliani de Cumis, M. Pini, and J. Waldie for illuminating discus-sions. This work was partially supported by the Flemish Science Foundation (FWO-Vl) and the Australian Government through the Australian Research Council Centre of Excellence in Future Low-Energy Electronics (Project No. CE170100039). ;			Approved	Most recent IF: 3.7; 2020 IF: 3.836
	Call Number	UA @ admin @ c:irua:168561			Serial	6517
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	Author	Singh, S.K.; Neek-Amal, M.; Costamagna, S.; Peeters, F.M.
	Title	Thermomechanical properties of a single hexagonal boron nitride sheet			Type	A1 Journal article
	Year	2013	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
	Volume	87	Issue	18	Pages	184106-184107
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Using atomistic simulations we investigate the thermodynamical properties of a single atomic layer of hexagonal boron nitride (h-BN). The thermal induced ripples, heat capacity, and thermal lattice expansion of large scale h-BN sheets are determined and compared to those found for graphene (GE) for temperatures up to 1000 K. By analyzing the mean-square height fluctuations < h(2)> and the height-height correlation function H(q) we found that the h-BN sheet is a less stiff material as compared to graphene. The bending rigidity of h-BN (i) is about 16% smaller than the one of GE at room temperature (300 K), and (ii) increases with temperature as in GE. The difference in stiffness between h-BN and GE results in unequal responses to external uniaxial and shear stress and different buckling transitions. In contrast to a GE sheet, the buckling transition of a h-BN sheet depends strongly on the direction of the applied compression. The molar heat capacity, thermal-expansion coefficient, and Gruneisen parameter are estimated to be 25.2 J mol(-1) K-1, 7.2 x 10(-6) K-1, and 0.89, respectively.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000318653800001	Publication Date	2013-05-08
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	80	Open Access
	Notes	; We thank K. H. Michel and D. A. Kirilenko for their useful comments on the manuscript. M. N.-A. was supported by EU-Marie Curie IIF Postdoctorate Fellowship No. 299855. S. Costamagna was supported by the Belgian Science Foundation (BELSPO). This work was supported by the ESF-EuroGRAPHENE project CONGRAN, the Flemish Science Foundation (FWO-Vl), and the Methusalem program of the Flemish Government. ;			Approved	Most recent IF: 3.836; 2013 IF: 3.664
	Call Number	UA @ lucian @ c:irua:109010			Serial	3638
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	Author	Zarenia, M.; Perali, A.; Neilson, D.; Peeters, F.M.
	Title	Enhancement of electron-hole superfluidity in double few-layer graphene			Type	A1 Journal article
	Year	2014	Publication	Scientific reports	Abbreviated Journal	Sci Rep-Uk
	Volume	4	Issue	4	Pages	7319
	Keywords	A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
	Abstract	We propose two coupled electron-hole sheets of few-layer graphene as a new nanostructure to observe superfluidity at enhanced densities and enhanced transition temperatures. For ABC stacked few-layer graphene we show that the strongly correlated electron-hole pairing regime is readily accessible experimentally using current technologies. We find for double trilayer and quadlayer graphene sheets spatially separated by a nano-thick hexagonal boron-nitride insulating barrier, that the transition temperature for electron-hole superfluidity can approach temperatures of 40 K.
	Address
	Corporate Author				Thesis
	Publisher	Nature Publishing Group	Place of Publication	London	Editor
	Language		Wos	000346272900001	Publication Date	2014-12-08
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2045-2322;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	4.259	Times cited	38	Open Access
	Notes	; We thank L. Benfatto, S. De Palo, and G. Senatore for helpful comments. This work was partially supported by the Flemish Science Foundation (FWO-Vl) and the European Science Foundation (POLATOM). ;			Approved	Most recent IF: 4.259; 2014 IF: 5.578
	Call Number	UA @ lucian @ c:irua:122743			Serial	1062
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	Author	Neek-Amal, M.; Peeters, F.M.
	Title	Strain-engineered graphene through a nanostructured substrate : 1 : deformations			Type	A1 Journal article
	Year	2012	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
	Volume	85	Issue	19	Pages	195445-195445,11
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Using atomistic simulations we investigate the morphological properties of graphene deposited on top of a nanostructured substrate. Sinusoidally corrugated surfaces, steps, elongated trenches, one-dimensional and cubic barriers, spherical bubbles, Gaussian bumps, and Gaussian depressions are considered as support structures for graphene. The graphene-substrate interaction is governed by van der Waals forces and the profile of the graphene layer is determined by minimizing the energy using molecular dynamics simulations. Based on the obtained optimum configurations, we found that (i) for graphene placed over sinusoidally corrugated substrates with corrugation wavelengths longer than 2 nm, the graphene sheet follows the substrate pattern while for supported graphene it is always suspended across the peaks of the substrate, (ii) the conformation of graphene to the substrate topography is enhanced when increasing the energy parameter in the van der Waals model, (iii) the adhesion of graphene into the trenches depends on the width of the trench and on the graphene's orientation, i. e., in contrast to a small-width (3 nm) nanoribbon with armchair edges, the one with zigzag edges follows the substrate profile, (iv) atomic-scale graphene follows a Gaussian bump substrate but not the substrate with a Gaussian depression, and (v) the adhesion energy due to van der Waals interaction varies in the range [0.1-0.4] J/m(2).
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000304394800012	Publication Date	2012-05-23
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	62	Open Access
	Notes	; We thank L. Covaci and S. Costamagna for valuable comments. We acknowledge M. Zarenia, M. R. Masir and D. Nasr for fruitful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl) and ESF EUROCORE program EuroGRAPHENE: CONGRAN. ;			Approved	Most recent IF: 3.836; 2012 IF: 3.767
	Call Number	UA @ lucian @ c:irua:98942			Serial	3166
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	Author	Földi, P.; Szaszkó-Bogár, V.; Peeters, F.M.
	Title	Spin-orbit interaction controlled properties of two-dimensional superlattices			Type	A1 Journal article
	Year	2010	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
	Volume	82	Issue	11	Pages	115302-115302,4
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The band structure of two-dimensional artificial superlattices in the presence of (Rashba-type) spin-orbit interaction (SOI) is presented. The position and shape of the energy bands in these spintronic crystals depend on the geometry as well as the strength of the SOI, which can be tuned by external gate voltages. For finite mesoscopic arrays, we show that their conductance properties and possible applications can be understood from these spin-dependent band diagrams.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000281516300005	Publication Date	2010-09-03
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	6	Open Access
	Notes	; We thank M. G. Benedict and F. Bartha for useful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP) and the Hungarian Scientific Research Fund (OTKA) under Contracts No. T81364 and No. M045596. P.F. was supported by a J. Bolyai grant of the Hungarian Academy of Sciences. ;			Approved	Most recent IF: 3.836; 2010 IF: 3.774
	Call Number	UA @ lucian @ c:irua:84259			Serial	3092
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	Author	Földi, P.; Szaszkó-Bogár, V.; Peeters, F.M.
	Title	High-temperature conductance of a two-dimensional superlattice controlled by spin-orbit interaction			Type	A1 Journal article
	Year	2011	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
	Volume	83	Issue	11	Pages	115313-115313,6
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Rashba-type spin-orbit interaction (SOI) controlled band structure of a two-dimensional superlattice allows for the modulation of the conductance of finite size devices by changing the strength of the SOI. We consider rectangular arrays and find that the temperature dependence of the conductance disappears for high temperatures, but the strength of the SOI still affects the conductance at these temperatures. The modulation effect can be seen even in the presence of strong dephasing, which can be important for practical applications.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000288242800007	Publication Date	2011-03-11
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	8	Open Access
	Notes	; We thank M. G. Benedict and F. Bartha for useful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the Hungarian Scientific Research Fund (OTKA) under Contracts No. T81364 and M045596 and by the “TAMOP-4.2.1/B-09/1/KONV-2010-0005 project: Creating the Center of Excellence at the University of Szeged” supported by the EU and the European Regional Development Fund. P.F. was supported by a J. Bolyai grant of the Hungarian Academy of Sciences. ;			Approved	Most recent IF: 3.836; 2011 IF: 3.691
	Call Number	UA @ lucian @ c:irua:88778			Serial	1466
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	Author	Van Pottelberge, R.; Peeters, F.M.
	Title	Tunable circular dipolelike system in graphene : mixed electron-hole states			Type	A1 Journal article
	Year	2019	Publication	Physical review B	Abbreviated Journal	Phys Rev B
	Volume	99	Issue	12	Pages	125426
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Coupled electron-hole states are realized in a system consisting of a combination of an electrostatic potential barrier and ring-shaped potential well, which resembles a circular dipole. A perpendicular magnetic field induces confined states inside the Landau gaps which are mainly located at the barrier or ring. Hybridizations between the barrier and ring states are seen as anticrossings in the energy spectrum. As a consequence, the energy levels show an oscillating dependence on the electrostatic potential strength in combination with an oscillating migration of the wave functions between the barrier and ring. At the anticrossing points the quantum state consists of a mixture of electron and hole. The present system mimics closely the behavior of a relativistic dipole on gapped graphene.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000462900200005	Publication Date	2019-03-27
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2469-9969; 2469-9950	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	3	Open Access
	Notes	; We thank M. Van der Donck for fruitful discussions. This work was supported by the Research Foundation of Flanders (FWO-V1) through an aspirant research grant for RVP. ;			Approved	Most recent IF: 3.836
	Call Number	UA @ admin @ c:irua:159409			Serial	5237
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	Author	Van Pottelberge, R.; Zarenia, M.; Vasilopoulos, P.; Peeters, F.M.
	Title	Graphene quantum dot with a Coulomb impurity : subcritical and supercritical regime			Type	A1 Journal article
	Year	2017	Publication	Physical review B	Abbreviated Journal	Phys Rev B
	Volume	95	Issue	24	Pages	245410
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We study the influence of confinement on the atomic collapse due to a Coulomb impurity placed at the center of a graphene quantum dot of radius R. We apply the zigzag or infinite-mass boundary condition and consider both a point-size and a finite-size impurity. As a function of the impurity strength Za, the energy spectra are discrete. In the case of the zigzag boundary condition, the degenerate (with respect to the angular momentum m) zero-energy levels are pulled down in energy as Z alpha increases, and they remain below epsilon = – Z alpha. Our results show that the energy levels exhibit a 1/R dependence in the subcritical regime [Z alpha < \|km + 1/2\|, k = 1 (-1) for the K (K') valley]. In the supercritical regime (Z alpha > \|km + 1/2\|) we find a qualitatively very different behavior where the levels decrease as a function of R in a nonmonotonic manner. While the valley symmetry is preserved in the presence of the impurity, we find that the impurity breaks electron-hole symmetry. We further study the energy spectrum of zigzag quantum dots in gapped graphene. Our results show that as the gap increases, the lowest electron states are pushed into the gap by the impurity.
	Address
	Corporate Author				Thesis
	Publisher	American Physical Society	Place of Publication	New York, N.Y	Editor
	Language		Wos	000403072400005	Publication Date	2017-06-13
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2469-9969; 2469-9950	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	13	Open Access
	Notes	; We thank Massoud Ramezani-Masir and Dean Moldovan for fruitful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl), the Methusalem funding of the Flemish Government, and by the Canadian NSERC Grant No. OGP0121756 (P. V.). ;			Approved	Most recent IF: 3.836
	Call Number	UA @ lucian @ c:irua:144197			Serial	4661
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	Author	Van Pottelberge, R.; Zarenia, M.; Peeters, F.M.
	Title	Magnetic field dependence of atomic collapse in bilayer graphene			Type	A1 Journal article
	Year	2018	Publication	Physical review B	Abbreviated Journal	Phys Rev B
	Volume	98	Issue	11	Pages	115406
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The spectrum of a Coulomb impurity in bilayer graphene is investigated as function of the strength of a perpendicular magnetic field for different values of the angular quantum number m and for different values of the gate voltage. We point out fundamental differences between the results from the two-band and four-band model. The supercritical instability and fall-to-center phenomena are investigated in the presence of a magnetic field. We find that in the four-band model the fall-to-center phenomenon occurs as in monolayer graphene, while this is not the case in the two-band model. We find that in a magnetic field the supercritical instability manifests itself as a series of anticrossings in the hole part of the spectrum for states coming from the low-energy band. However, we also find very distinct anticrossings in the electron part of the spectrum that continue into the hole part, which are related to the higher energy band of the four-band model. At these anticrossings, we find a very sharp peak in the probability density close to the impurity, reminiscent for the fall-to-center phenomenon. In this paper, these peculiar and interesting effects are studied for different magnetic field, interlayer coupling, and bias potential strengths.
	Address
	Corporate Author				Thesis
	Publisher	American Physical Society	Place of Publication	New York, N.Y	Editor
	Language		Wos	000443671900010	Publication Date	2018-09-04
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2469-9969; 2469-9950	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	3	Open Access
	Notes	; We thank Matthias Van der Donck and Ben Van Duppen for fruitful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem funding of the Flemish Government. ;			Approved	Most recent IF: 3.836
	Call Number	UA @ lucian @ c:irua:153654UA @ admin @ c:irua:153654			Serial	5113
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	Author	Van Pottelberge, R.; Zarenia, M.; Peeters, F.M.
	Title	Comment on “Impurity spectra of graphene under electric and magnetic fields”			Type	Editorial
	Year	2018	Publication	Physical review B	Abbreviated Journal	Phys Rev B
	Volume	97	Issue	20	Pages	207403
	Keywords	Editorial; Condensed Matter Theory (CMT)
	Abstract	In a recent paper [Phys. Rev. B 89, 155403 (2014)], the authors investigated the spectrum of a Coulomb impurity in graphene in the presence of magnetic and electric fields using the coupled series expansion approach. In the first part of their paper, they investigated how Coulomb impurity states collapse in the presence of a perpendicular magnetic field. We argue that the obtained spectrum does not give information about the atomic collapse and that their interpretation of the spectrum regarding atomic collapse is not correct. We also argue that the obtained results are only valid up to the dimensionless charge vertical bar alpha vertical bar = 0.5 and, to obtain correct results for alpha > 0.5, a proper regularization of the Coulomb interaction is required. Here we present the correct numerical results for the spectrum for arbitrary values of alpha.
	Address
	Corporate Author				Thesis
	Publisher	Amer physical soc	Place of Publication	College pk	Editor
	Language		Wos	000433288800015	Publication Date	2018-05-29
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2469-9969; 2469-9950	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	5	Open Access
	Notes	; We thank Matthias Van der Donck for fruitful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem funding of the Flemish Government. ;			Approved	Most recent IF: 3.836
	Call Number	UA @ lucian @ c:irua:152042UA @ admin @ c:irua:152042			Serial	5017
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	Author	Van Pottelberge, R.; Van Duppen, B.; Peeters, F.M.
	Title	Electrical dipole on gapped graphene : bound states and atomic collapse			Type	A1 Journal article
	Year	2018	Publication	Physical review B	Abbreviated Journal	Phys Rev B
	Volume	98	Issue	16	Pages	165420
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We investigate the energy spectrum, wave functions, and local density of states of an electrical dipole placed on a sheet of gapped graphene as function of the charge strength Z alpha for different sizes of the dipole and for different regularization parameters. The dipole is modeled as consisting of a positive and negative charge. Bound states are found within the gap region with some energy levels that anticross and others that cross as function of the impurity strength Z alpha. The anticrossings are more pronounced and move to higher charges Z alpha when the length of the dipole decreases. These energy levels turn into atomic collapse states when they enter the positive (or negative) energy continuum. A smooth transition from the single-impurity behavior to the dipole one is observed: The states diving towards the continuum in the single-impurity case are gradually replaced by a series of anticrossings that represent a continuation of the diving states in the single-impurity case. By studying the local density of states at the edge of the dipole we show how the series of anticrossings persist in the positive and negative continuum.
	Address
	Corporate Author				Thesis
	Publisher	American Physical Society	Place of Publication	New York, N.Y	Editor
	Language		Wos	000447302700010	Publication Date	2018-10-23
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2469-9969; 2469-9950	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	8	Open Access
	Notes	; We thank Matthias Van der Donck for fruitful discussions. This work was supported by the Research Foundation of Flanders (FWO-V1) through an aspirant research grant for R.V.P. and a postdoctoral grant for B.V.D. ;			Approved	Most recent IF: 3.836
	Call Number	UA @ lucian @ c:irua:154728UA @ admin @ c:irua:154728			Serial	5094
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	Author	Van Pottelberge, R.; Moldovan, D.; Milovanović, S.P.; Peeters, F.M.
	Title	Molecular collapse in monolayer graphene			Type	A1 Journal article
	Year	2019	Publication	2D materials	Abbreviated Journal	2D Mater
	Volume	6	Issue	4	Pages	045047
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Atomic collapse is a phenomenon inherent to relativistic quantum mechanics where electron states dive in the positron continuum for highly charged nuclei. This phenomenon was recently observed in graphene. Here we investigate a novel collapse phenomenon when multiple sub- and supercritical charges of equal strength are put close together as in a molecule. We construct a phase diagram which consists of three distinct regions: (1) subcritical, (2) frustrated atomic collapse, and (3) molecular collapse. We show that the single impurity atomic collapse resonances rearrange themselves to form molecular collapse resonances which exhibit a distinct bonding, anti-bonding and non-bonding character. Here we limit ourselves to systems consisting of two and three charges. We show that by tuning the distance between the charges and their strength a high degree of control over the molecular collapse resonances can be achieved.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000487692200003	Publication Date	2019-08-30
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2053-1583	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	6.937	Times cited	6	Open Access
	Notes	; We thank Matthias Van der Donck for fruitful discussions. This work was supported by the Research Foundation of Flanders (FWO-V1) through an aspirant research Grant for RVP and a postdoctoral Grant for SPM. ;			Approved	Most recent IF: 6.937
	Call Number	UA @ admin @ c:irua:163756			Serial	5422
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	Author	Conti, S.; Perali, A.; Peeters, F.M.; Neilson, D.
	Title	Multicomponent electron-hole superfluidity and the BCS-BEC crossover in double bilayer graphene			Type	A1 Journal article
	Year	2017	Publication	Physical review letters	Abbreviated Journal	Phys Rev Lett
	Volume	119	Issue	25	Pages	257002
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	<script type='text/javascript'>document.write(unpmarked('Superfluidity in coupled electron-hole sheets of bilayer graphene is predicted here to be multicomponent because of the conduction and valence bands. We investigate the superfluid crossover properties as functions of the tunable carrier densities and the tunable energy band gap Eg. For small band gaps there is a significant boost in the two superfluid gaps, but the interaction-driven excitations from the valence to the conduction band can weaken the superfluidity, even blocking the system from entering the Bose-Einstein condensate (BEC) regime at low densities. At a given larger density, a band gap E-g similar to 80-120 meV can carry the system into the strong-pairing multiband BCS-BEC crossover regime, the optimal range for realization of high-Tc superfluidity.'));
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	New York, N.Y.	Editor
	Language		Wos	000418619100017	Publication Date	2017-12-22
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0031-9007	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	8.462	Times cited	18	Open Access
	Notes	; We thank Mohammad Zarenia for useful discussions. Part of this work was supported by FWO-VI (Flemish Science Foundation) and the Methusalem program. ;			Approved	Most recent IF: 8.462
	Call Number	UA @ lucian @ c:irua:148509			Serial	4885
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	Author	Xu, B.; Milošević, M.V.; Lin, S.-H.; Peeters, F.M.; Jankó, B.
	Title	Formation of multiple-flux-quantum vortices in mesoscopic superconductors from simulations of calorimetric, magnetic, and transport properties			Type	A1 Journal article
	Year	2011	Publication	Physical review letters	Abbreviated Journal	Phys Rev Lett
	Volume	107	Issue	5	Pages	057002,1-057002,4
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Because of strong flux confinement in mesoscopic superconductors, a giant vortex may appear in the ground state of the system in an applied magnetic field. This multiquanta vortex can then split into individual vortices (and vice versa) as a function of, e.g., applied current, magnetic field, or temperature. Here we show that such transitions can be identified by calorimetry, as the formation or splitting of a giant vortex results in a clear jump in measured heat capacity versus external drive. We attribute this phenomenon to an abrupt change in the density of states of the quasiparticle excitations in the vortex core(s), and further link it to a sharp change of the magnetic susceptibility at the transitionproving that the formation of a giant vortex can also be detected by magnetometry.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	New York, N.Y.	Editor
	Language		Wos	000293333100006	Publication Date	2011-07-29
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0031-9007;1079-7114;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	8.462	Times cited	26	Open Access
	Notes	; We thank O. Bourgeois, T. Yokoyama, M. Eschrig, and M. Ichioka for discussions. This work was supported by FWO-Vlaanderen, the Belgian Science Policy (IAP), the bilateral project Flanders-USA, NSF NIRT, ECS-0609249, and Institute of Theoretical Sciences, Notre Dame. ;			Approved	Most recent IF: 8.462; 2011 IF: 7.370
	Call Number	UA @ lucian @ c:irua:91237			Serial	1263
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	Author	Ghosh, S.; Tongay, S.; Hebard, A.F.; Sahin, H.; Peeters, F.M.
	Title	Ferromagnetism in stacked bilayers of Pd/C₆₀			Type	A1 Journal article
	Year	2014	Publication	Journal of magnetism and magnetic materials	Abbreviated Journal	J Magn Magn Mater
	Volume	349	Issue		Pages	128-134
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We provide experimental evidence for the existence of ferromagnetism in bilayers of Pd/C-60 which is supported by theoretical calculations based on density functional theory (DFT). The observed ferromagnetism is surprising as C-60 and Pd films are both non-ferromagnetic in the non-interacting limit. Magnetization (M) versus applied field (H) data acquired at different temperatures (T) show magnetic hysteresis with typical coercive fields (H-c) on the order of 50 Oe. From the temperature-dependent magnetization M(T) we extract a Curie temperature (T-c >= 550 K) using Bloch-like power law extrapolations to high temperatures. Using DFT calculations we investigated all plausible scenarios for the interaction between the C-60 molecules and the Pd slabs, Pd single atoms and Pd clusters. DFT shows that while the C-60 molecules are nonmagnetic, Pd films have a degenerate ground state that subject to a weak perturbation, can become ferromagnetic. Calculations also show that the interaction of C-60 molecules with excess Pd atoms and with sharp edges of a Pd slab is the most likely configuration that render the system ferromagnetic Interestingly, the calculated charge transfer (0.016 e per surface Pd atom, 0.064 e per Pd for intimate contact region) between C-60 and Pd does not appear to play an important role. (C) 2013 Elsevier B.V. All rights reserved.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000326037600022	Publication Date	2013-08-02
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0304-8853;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.63	Times cited	8	Open Access
	Notes	; We thank Prof. Amlan Biswas and Daniel Grant for Atomic Force Microscopy measurements. This work is supported by the National Science Foundation (NSF) under Contract Number 1005301 (AFH). The authors also thank S. Ciraci for fruitful discussions. All the computational resources have been provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H. Sahin is also supported by a FWO Pegasus Marie Curie Long Fellowship during the study. ;			Approved	Most recent IF: 2.63; 2014 IF: 1.970
	Call Number	UA @ lucian @ c:irua:112214			Serial	1184
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	Author	Van Duppen, B.; Peeters, F.M.
	Title	Klein paradox for a pn junction in multilayer graphene			Type	A1 Journal article
	Year	2013	Publication	Europhysics letters	Abbreviated Journal	Epl-Europhys Lett
	Volume	102	Issue	2	Pages	27001-27005
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Charge carriers in single and multilayered graphene systems behave as chiral particles due to the particular lattice symmetry of the crystal. We show that the interplay between the meta-material properties of graphene multilayers and the pseudospinorial properties of the charge carriers result in the occurrence of Klein and anti-Klein tunneling for rhombohedral stacked multilayers. We derive an algebraic formula predicting the angles at which these phenomena occur and support this with numerical calculations for systems up to four layers. We present a decomposition of an arbitrarily stacked multilayer into pseudospin doublets that have the same properties as rhombohedral systems with a lower number of layers. Copyright (C) EPLA, 2013
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Paris	Editor
	Language		Wos	000319617700017	Publication Date	2013-05-02
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0295-5075;1286-4854;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.957	Times cited	17	Open Access
	Notes	; We thank S. GILLIS for valuable discussions. This work was supported by the European Science Foundation (ESF) under the EUROCORES Program Euro-GRAPHENE within the project CONGRAN, the Flemish Science Foundation (FWO-Vl) by an aspirant research grant to B. Van Duppen and the Methusalem Programme of the Flemish Government. ;			Approved	Most recent IF: 1.957; 2013 IF: 2.269
	Call Number	UA @ lucian @ c:irua:109665			Serial	1763
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