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	Author	Berdiyorov, G.R.; de Romaguera, A.R.C.; Milošević, M.V.; Doria, M.M.; Covaci, L.; Peeters, F.M.
	Title	Dynamic and static phases of vortices under an applied drive in a superconducting stripe with an array of weak links			Type	A1 Journal article
	Year	2012	Publication	European physical journal : B : condensed matter and complex systems	Abbreviated Journal	Eur Phys J B
	Volume	85	Issue	4	Pages	130-130,8
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Static and dynamic properties of superconducting vortices in a superconducting stripe with a periodic array of weakly-superconducting (or normal metal) regions are studied in the presence of external magnetic and electric fields. The time-dependent Ginzburg-Landau theory is used to describe the electronic transport, where the anisotropy is included through the spatially-dependent critical temperature T-c. Superconducting vortices penetrating into the weak-superconducting region with smaller T-c are more mobile than the ones in the strong superconducting regions. We observe periodic entrance and exit of vortices which reside in the weak link for some short interval. The mobility of the weakly-pinned vortices can be reduced by increasing the uniform applied magnetic field leading to distinct features in the voltage vs. magnetic field response of the system.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Berlin	Editor
	Language		Wos	000303545400013	Publication Date	2012-04-20
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1434-6028;1434-6036;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.461	Times cited	32	Open Access
	Notes	; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the bilateral programme between Flanders and Brazil. G.R.B. and L.C. acknowledge individual support from FWO-Vl. A.R.de C.R. acknowledges CNPq and FACEPE for financial support. ;			Approved	Most recent IF: 1.461; 2012 IF: 1.282
	Call Number	UA @ lucian @ c:irua:98267			Serial	761
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	Author	Kim, W.; Covaci, L.; Dogan, F.; Marsiglio, F.
	Title	Quantum mechanics of spin transfer in coupled electron-spin chains			Type	A1 Journal article
	Year	2007	Publication	Epl	Abbreviated Journal	Epl-Europhys Lett
	Volume	79	Issue	6	Pages	67004
	Keywords	A1 Journal article
	Abstract	The manner in which spin-polarized electrons interact with a magnetized thin film is currently described by a semi-classical approach. This in turn provides our present understanding of the spin transfer, or spin torque phenomenon. However, spin is an intrinsically quantum-mechanical quantity. Here, we make the first strides towards a fully quantum-mechanical description of spin transfer through spin currents interacting with a Heisenberg-coupled spin chain. Because of quantum entanglement, this requires a formalism based on the density matrix approach. Our description illustrates how individual spins in the chain time-evolve as a result of spin transfer.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000250409500023	Publication Date	2007-08-24
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0295-5075	ISBN		Additional Links
	Impact Factor	1.957	Times cited	3	Open Access
	Notes				Approved	Most recent IF: 1.957; 2007 IF: 2.206
	Call Number	UA @ lucian @			Serial	4430
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	Author	Covaci, L.; Berciu, M.
	Title	Holstein polaron: The effect of coupling to multiple-phonon modes			Type	A1 Journal article
	Year	2007	Publication	Epl	Abbreviated Journal	Epl-Europhys Lett
	Volume	80	Issue	6	Pages	67001
	Keywords	A1 Journal article
	Abstract	We investigate the effects of coupling to multiple-phonon modes on the properties of a Holstein polaron. To this end, we generalize the Momentum Average approximations MA((0)) and MA((1)) to deal with multiple-phonon modes. As for a single-phonon mode, these approximations are found to be numerically very efficient. They become exact for very weak or very strong couplings, and are highly accurate in the intermediate regimes, e.g. the spectral weights obey exactly the first six, respectively eight, sum rules. Our results show that the effect on ground-state properties is cumulative in nature. As a result, if the effective coupling to one mode is much larger than to all the others, this mode effectively determines the ground-state properties. However, even very weak coupling to a second phonon mode has important non-perturbational effects on the higher-energy spectrum, in particular on the dispersion and the phonon statistics of the polaron band. This has important consequences on the analysis and interpretation of data for real materials.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000251648300016	Publication Date	2007-11-30
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0295-5075	ISBN		Additional Links
	Impact Factor	1.957	Times cited	9	Open Access
	Notes				Approved	Most recent IF: 1.957; 2007 IF: 2.206
	Call Number	UA @ lucian @			Serial	4431
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	Author	Zhang, L.-F.; Covaci, L.; Peeters, F.M.
	Title	Position-dependent effect of non-magnetic impurities on superconducting properties of nanowires			Type	A1 Journal article
	Year	2015	Publication	Europhysics letters	Abbreviated Journal	Epl-Europhys Lett
	Volume	109	Issue	109	Pages	17010
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Anderson's theorem states that non-magnetic impurities do not change the bulk properties of conventional superconductors. However, as the dimensionality is reduced, the effect of impurities becomes more significant. Here we investigate superconducting nanowires with diameter comparable to the Fermi wavelength $\lambda_F$ (which is less than the superconducting coherence length) by using a microscopic description based on the Bogoliubov-de Gennes method. We find that: 1) impurities strongly affect the superconducting properties, 2) the effect is impurity position dependent, and 3) it exhibits opposite behavior for resonant and off-resonant wire widths. We show that this is due to the interplay between the shape resonances of the order parameter and the subband energy spectrum induced by the lateral quantum confinement. These effects can be used to manipulate the Josephson current, filter electrons by subband and investigate the symmetries of the superconducting subband gaps.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Paris	Editor
	Language		Wos	000348592100029	Publication Date	2015-01-21
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0295-5075	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.957	Times cited	7	Open Access
	Notes	; This work was supported by the Flemish Science Foundation (FWO-Vlaanderen) and the Methusalem funding of the Flemish Government. ;			Approved	Most recent IF: 1.957; 2015 IF: 2.095
	Call Number	UA @ lucian @ c:irua:128424			Serial	4227
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	Author	Andelkovic, M.; Milovanović, S.P.; Covaci, L.; Peeters, F.M.
	Title	Double moiré with a twist : supermoiré in encapsulated graphene			Type	A1 Journal article
	Year	2020	Publication	Nano Letters	Abbreviated Journal	Nano Lett
	Volume	20	Issue	2	Pages	979
	Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
	Abstract	A periodic spatial modulation, as created by a moire pattern, has been extensively studied with the view to engineer and tune the properties of graphene. Graphene encapsulated by hexagonal boron nitride (hBN) when slightly misaligned with the top and bottom hBN layers experiences two interfering moire patterns, resulting in a so-called supermoire (SM). This leads to a lattice and electronic spectrum reconstruction. A geometrical construction of the nonrelaxed SM patterns allows us to indicate qualitatively the induced changes in the electronic properties and to locate the SM features in the density of states and in the conductivity. To emphasize the effect of lattice relaxation, we report band gaps at all Dirac-like points in the hole doped part of the reconstructed spectrum, which are expected to be enhanced when including interaction effects. Our result is able to distinguish effects due to lattice relaxation and due to the interfering SM and provides a clear picture on the origin of recently experimentally observed effects in such trilayer heterostuctures.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000514255400021	Publication Date	2020-01-21
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1530-6984	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	10.8	Times cited	33	Open Access	OpenAccess
	Notes	; This work was funded by FLAGERA project TRANS2DTMD and the Flemish Science Foundation (FWO-Vl) through a postdoc fellowship for S.P.M. The authors acknowledge useful discussions with W. Zihao and K. Novoselov. ;			Approved	Most recent IF: 10.8; 2020 IF: 12.712
	Call Number	UA @ admin @ c:irua:168685			Serial	6490
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	Author	Villarreal, R.; Lin, P.-C.; Faraji, F.; Hassani, N.; Bana, H.; Zarkua, Z.; Nair, M.N.; Tsai, H.-C.; Auge, M.; Junge, F.; Hofsaess, H.C.; De Gendt, S.; De Feyter, S.; Brems, S.; Ahlgren, E.H.; Neyts, E.C.; Covaci, L.; Peeters, F.M.; Neek-Amal, M.; Pereira, L.M.C.
	Title	Breakdown of universal scaling for nanometer-sized bubbles in graphene			Type	A1 Journal article
	Year	2021	Publication	Nano Letters	Abbreviated Journal	Nano Lett
	Volume	21	Issue	19	Pages	8103-8110
	Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	We report the formation of nanobubbles on graphene with a radius of the order of 1 nm, using ultralow energy implantation of noble gas ions (He, Ne, Ar) into graphene grown on a Pt(111) surface. We show that the universal scaling of the aspect ratio, which has previously been established for larger bubbles, breaks down when the bubble radius approaches 1 nm, resulting in much larger aspect ratios. Moreover, we observe that the bubble stability and aspect ratio depend on the substrate onto which the graphene is grown (bubbles are stable for Pt but not for Cu) and trapped element. We interpret these dependencies in terms of the atomic compressibility of the noble gas as well as of the adhesion energies between graphene, the substrate, and trapped atoms.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000709549100026	Publication Date	2021-09-14
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1530-6984	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	12.712	Times cited	12	Open Access	OpenAccess
	Notes				Approved	Most recent IF: 12.712
	Call Number	UA @ admin @ c:irua:184137			Serial	6857
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	Author	Milovanović, S.P.; Covaci, L.; Peeters, F.M.
	Title	Strain fields in graphene induced by nanopillar mesh			Type	A1 Journal article
	Year	2019	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	125	Issue	8	Pages	082534
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The mechanical and electronic properties of a graphene membrane placed on top of a triangular superlattice of nanopillars are investigated. We use molecular dynamics simulations to access the deformation fields and the tight-binding approaches to calculate the electronic properties. Ripples form in the graphene layer that span across the unit cell, connecting neighboring pillars, in agreement with recent experiments. We find that the resulting pseudo-magnetic field (PMF) varies strongly across the unit cell. We investigate the dependence of PMF on unit cell boundary conditions, height of the pillars, and the strength of the van der Waals interaction between graphene and the substrate. We find direct correspondence with typical experiments on pillars, showing intrinsic “slack” in the graphene membrane. PMF values are confirmed by the local density of states calculations performed at different positions of the unit cell showing pseudo-Landau levels with varying spacings. Our findings regarding the relaxed membrane configuration and the induced strains are transferable to other flexible 2D membranes.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000460033800038	Publication Date	2019-01-16
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979; 1089-7550	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	5	Open Access
	Notes	; S.P.M. is supported by the Flemish Science Foundation (FWO). ;			Approved	Most recent IF: 2.068
	Call Number	UA @ admin @ c:irua:158605			Serial	5231
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	Author	de Sousa, J.S.; Covaci, L.; Peeters, F.M.; Farias, G.A.
	Title	Time-dependent investigation of charge injection in a quantum dot containing one electron			Type	A1 Journal article
	Year	2012	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	112	Issue	9	Pages	093705-93709
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The interaction of an injected electron towards a quantum dot (QD) containing a single confined electron is investigated using a flexible time-dependent quantum mechanics formalism, which allows both electrons to move and undergo quantum transitions. Different scenarios combining quantum dot dimensions, dielectric constant, injected wave packet energy, and width were explored, and our main results are: (i) due to the large characteristic transitions times between the confined state in the quantum dot and the delocalized state in the continuum, it is relatively difficult to ionize the occupied QD by Coulomb interaction solely and (ii) the charging state of the quantum dot can be sensed by direct injection of charges. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4759292]
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000311968400052	Publication Date	2012-11-06
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	1	Open Access
	Notes	; This work was financially supported by the Brazilian National Research Council (CNPq), under Contract No. NanoBioEstruturas 555183/2005-0, Fundao Cearense de Apoio ao Desenvolvimento Cientfico e Tecnolgico (Funcap), CAPES, Pronex/CNPq/ Funcap, the Bilateral program between Flanders and Brazil, and the Flemish Science Foundation (FWO). ;			Approved	Most recent IF: 2.068; 2012 IF: 2.210
	Call Number	UA @ lucian @ c:irua:106014			Serial	3664
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	Author	Nasr Esfahani, D.; Covaci, L.; Peeters, F.M.
	Title	Surface correlation effects in two-band strongly correlated slabs			Type	A1 Journal article
	Year	2014	Publication	Journal of physics : condensed matter	Abbreviated Journal	J Phys-Condens Mat
	Volume	26	Issue	7	Pages	075601-75609
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Using an extension of the Gutzwiller approximation for an inhomogeneous system, we study the two-band Hubbard model with unequal band widths for a slab geometry. The aim is to investigate the mutual effect of individual bands on the spatial distribution of quasi-particle weight and charge density, especially near the surface of the slab. The main effect of the difference in band width is the presence of two different length scales corresponding to the quasi-particle profile of each band. This is enhanced in the vicinity of the critical interaction of the narrow band where an orbitally selective Mott transition occurs and a surface dead layer forms for the narrow band. For the doped case, two different regimes of charge transfer between the surface and the bulk of the slab are revealed. The charge transfer from surface/ center to center/ surface depends on both the doping level and the average relative charge accumulated in each band. Such effects could also be of importance when describing the accumulation of charges at the interface between structures made of multi-band strongly correlated materials.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	London	Editor
	Language		Wos	000330719500009	Publication Date	2014-01-29
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0953-8984;1361-648X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.649	Times cited	1	Open Access
	Notes	; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem program of the Flemish government. One of us (LC) is a postdoctoral fellow of the FWO-Vl. ;			Approved	Most recent IF: 2.649; 2014 IF: 2.346
	Call Number	UA @ lucian @ c:irua:115723			Serial	3395
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	Author	Chaves, A.; Moura, V.N.; Linard, F.J.A.; Covaci, L.; Milošević, M.V.
	Title	Tunable magnetic focusing using Andreev scattering in superconductor-graphene hybrid devices			Type	A1 Journal article
	Year	2020	Publication	Journal Of Applied Physics	Abbreviated Journal	J Appl Phys
	Volume	128	Issue	12	Pages	124303
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
	Abstract	We perform the wavepacket dynamics simulation of a graphene-based device where propagating electron trajectories are tamed by an applied magnetic field toward a normal/superconductor interface. The magnetic field controls the incidence angle of the incoming electronic wavepacket at the interface, which results in the tunable electron-hole ratio in the reflected wave function due to the angular dependence of the Andreev reflection. Here, mapped control of the quasiparticle trajectories by the external magnetic field not only defines an experimental probe for fundamental studies of the Andreev reflection in graphene but also lays the foundation for further development of magnetic focusing devices based on nanoengineered superconducting two-dimensional materials.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000576393200002	Publication Date	2020-09-28
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979; 1089-7550	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.2	Times cited	1	Open Access	Not_Open_Access
	Notes	; This work was supported by the Brazilian Council for Research (CNPq) through the PRONEX/FUNCAP and PQ programs and by the Research Foundation-Flanders (FWO). ;			Approved	Most recent IF: 3.2; 2020 IF: 2.068
	Call Number	UA @ admin @ c:irua:172730			Serial	6639
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	Author	Costamagna, S.; Schulz, A.; Covaci, L.; Peeters, F.
	Title	Partially unzipped carbon nanotubes as magnetic field sensors			Type	A1 Journal article
	Year	2012	Publication	Applied physics letters	Abbreviated Journal	Appl Phys Lett
	Volume	100	Issue	23	Pages	232104-232104,3
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The conductance through graphene nanoribbons (GNR) connected to a partially unzipped carbon nanotube (CNT) is studied in the presence of an external magnetic field applied parallel to the long axis of the tube by means of non-equilibrium Green's function technique. We consider CNTs that are partially unzipped to form armchair-GNR/zigzag-CNT/armchair-GNR or zigzag-GNR/armchair-CNT/zigzag-GNR junctions. We find that the inclusion of a longitudinal magnetic field affects the electronic states only in the CNT region, leading to the suppression of the conductance at low energies. We demonstrate that both types of junctions can be used as magnetic field sensors. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4726039]
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000305089900038	Publication Date	2012-06-07
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0003-6951;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.411	Times cited	10	Open Access
	Notes	; L.C. acknowledges support from the Flemish Science Foundation (FWO-Vl) and S.C. from the Belgian Science Foundation (BELSPO). This work is supported by the ESF-EuroGRAPHENE Project CONGRAN. ;			Approved	Most recent IF: 3.411; 2012 IF: 3.794
	Call Number	UA @ lucian @ c:irua:99083			Serial	2556
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	Author	Homm, P.; Dillemans, L.; Menghini, M.; Van Bilzen, B.; Bakalov, P.; Su, C.Y.; Lieten, R.; Houssa, M.; Nasr Esfahani, D.; Covaci, L.; Peeters, F.M.; Seo, J.W.; Locquet, J.P.;
	Title	Collapse of the low temperature insulating state in Cr-doped V₂O₃ thin films			Type	A1 Journal article
	Year	2015	Publication	Applied physics letters	Abbreviated Journal	Appl Phys Lett
	Volume	107	Issue	107	Pages	111904
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We have grown epitaxial Cr-doped V2O3 thin films with Cr concentrations between 0% and 20% on (0001)-Al2O3 by oxygen-assisted molecular beam epitaxy. For the highly doped samples (>3%), a regular and monotonous increase of the resistance with decreasing temperature is measured. Strikingly, in the low doping samples (between 1% and 3%), a collapse of the insulating state is observed with a reduction of the low temperature resistivity by up to 5 orders of magnitude. A vacuum annealing at high temperature of the films recovers the low temperature insulating state for doping levels below 3% and increases the room temperature resistivity towards the values of Cr-doped V2O3 single crystals. It is well-know that oxygen excess stabilizes a metallic state in V2O3 single crystals. Hence, we propose that Cr doping promotes oxygen excess in our films during deposition, leading to the collapse of the low temperature insulating state at low Cr concentrations. These results suggest that slightly Cr-doped V2O3 films can be interesting candidates for field effect devices. (C) 2015 AIP Publishing LLC.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000361639200020	Publication Date	2015-09-19
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0003-6951; 1077-3118	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.411	Times cited	14	Open Access
	Notes	; The authors acknowledge financial support from the FWO Project No. G052010N10 as well as the EU-FP7 SITOGA Project. P.H. acknowledges support from Becas Chile-CONICYT. ;			Approved	Most recent IF: 3.411; 2015 IF: 3.302
	Call Number	UA @ lucian @ c:irua:128728			Serial	4149
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	Author	Joao, S.M.; Andelkovic, M.; Covaci, L.; Rappoport, T.G.; Lopes, J.M.V.P.; Ferreira, A.
	Title	KITE : high-performance accurate modelling of electronic structure and response functions of large molecules, disordered crystals and heterostructures			Type	A1 Journal article
	Year	2020	Publication	Royal Society Open Science	Abbreviated Journal	Roy Soc Open Sci
	Volume	7	Issue	2	Pages	191809-191832
	Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
	Abstract	We present KITE, a general purpose open-source tight-binding software for accurate real-space simulations of electronic structure and quantum transport properties of large-scale molecular and condensed systems with tens of billions of atomic orbitals (N similar to 10(10)). KITE's core is written in C++, with a versatile Python-based interface, and is fully optimized for shared memory multi-node CPU architectures, thus scalable, efficient and fast. At the core of KITE is a seamless spectral expansion of lattice Green's functions, which enables large-scale calculations of generic target functions with uniform convergence and fine control over energy resolution. Several functionalities are demonstrated, ranging from simulations of local density of states and photo-emission spectroscopy of disordered materials to large-scale computations of optical conductivity tensors and real-space wave-packet propagation in the presence of magneto-static fields and spin-orbit coupling. On-the-fly calculations of real-space Green's functions are carried out with an efficient domain decomposition technique, allowing KITE to achieve nearly ideal linear scaling in its multi-threading performance. Crystalline defects and disorder, including vacancies, adsorbates and charged impurity centres, can be easily set up with KITE's intuitive interface, paving the way to user-friendly large-scale quantum simulations of equilibrium and non-equilibrium properties of molecules, disordered crystals and heterostructures subject to a variety of perturbations and external conditions.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000518020200001	Publication Date	2020-02-26
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2054-5703	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.5	Times cited	19	Open Access	OpenAccess
	Notes	; T.G.R. and A.F. acknowledge support from the Newton Fund and the Royal Society through the Newton Advanced Fellowship scheme (ref. no. NA150043). M.A. and L.C. acknowledge support from the Trans2DTMD FlagEra project and the VSC (Flemish Supercomputer Center). A.F. acknowledges support from the Royal Society through a University Research Fellowship (ref. nos. UF130385 and URF-R-191021) and an Enhancement Award (ref. no. RGF-EA-180276). T.G.R. acknowledges the support from the Brazilian agencies CNPq and FAPERJ and COMPETE2020, PORTUGAL2020, FEDER and the Portuguese Foundation for Science and Technology (FCT) through project POCI-01-0145-FEDER-028114. S.M.J. is supported by Fundacao para a Ciencia e Tecnologia (FCT) under the grant no. PD/BD/142798/ 2018. S.M.J. and J.M.V.P.L. acknowledge financial support from the FCT, COMPETE 2020 programme in FEDER component (European Union), through projects POCI-01-0145-FEDER028887 and UID/FIS/04650/2013. S.M.J. and J.M.V.P.L. further acknowledge financial support from FCT through national funds, co-financed by COMPETE-FEDER (grant no. M-ERANET2/0002/2016 -UltraGraf) under the Partnership Agreement PT2020. ;			Approved	Most recent IF: 3.5; 2020 IF: 2.243
	Call Number	UA @ admin @ c:irua:167751			Serial	6556
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	Author	Milovanović, S.P.; Andelkovic, M.; Covaci, L.; Peeters, F.M.
	Title	Band flattening in buckled monolayer graphene			Type	A1 Journal article
	Year	2020	Publication	Physical Review B	Abbreviated Journal	Phys Rev B
	Volume	102	Issue	24	Pages	245427
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
	Abstract	The strain fields of periodically buckled graphene induce a periodic pseudomagnetic field (PMF) that modifies the electronic band structure. From the geometry, amplitude, and period of the periodic pseudomagnetic field, we determine the necessary conditions to access the regime of correlated phases by examining the band flattening. As compared to twisted bilayer graphene the proposed system has the advantages that (1) only a single layer of graphene is needed, (2) one is not limited to hexagonal superlattices, and (3) narrower flat bandwidth and larger separation between flat bands can be induced. We, therefore, propose that periodically strained graphene single layers can become a platform for the exploration of exotic many-body phases.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000602844600007	Publication Date	2020-12-28
	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	11	Open Access	OpenAccess
	Notes	; S.P.M. is supported by the Flemish Science Foundation (FWO). We thank E. Y. Andrei, Y. Jiang, and J. Mao for fruitful discussions. ;			Approved	Most recent IF: 3.7; 2020 IF: 3.836
	Call Number	UA @ admin @ c:irua:175021			Serial	6684
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	Author	Linard, F.J.A.; Moura, V.N.; Covaci, L.; Milošević, M.V.; Chaves, A.
	Title	Wave-packet scattering at a normal-superconductor interface in two-dimensional materials : a generalized theoretical approach			Type	A1 Journal article
	Year	2023	Publication	Physical review B	Abbreviated Journal
	Volume	107	Issue	16	Pages	165306-165309
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
	Abstract	A wave-packet time evolution method, based on the split-operator technique, is developed to investigate the scattering of quasiparticles at a normal-superconductor interface of arbitrary profile and shape. As a practical application, we consider a system where low-energy electrons can be described as Dirac particles, which is the case for most two-dimensional materials, such as graphene and transition-metal dichalcogenides. However, the method is easily adapted for other cases such as electrons in few-layer black phosphorus or any Schrodinger quasiparticles within the effective mass approximation in semiconductors. We employ the method to revisit Andreev reflection in mono-, bi-, and trilayer graphene, where specular-and retro-reflection cases are observed for electrons scattered by a steplike superconducting region. The effect of opening a zero-gap channel across the superconducting region on the electron and hole scattering is also addressed, as an example of the versatility of the technique proposed here.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000974675700006	Publication Date	2023-04-14
	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		Open Access	OpenAccess
	Notes				Approved	Most recent IF: 3.7; 2023 IF: 3.836
	Call Number	UA @ admin @ c:irua:196709			Serial	8954
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	Author	Bakalov, P.; Esfahani, D.N.; Covaci, L.; Peeters, F.M.; Tempere, J.; Locquet, J.-P.
	Title	Electric-field-driven Mott metal-insulator transition in correlated thin films : an inhomogeneous dynamical mean-field theory approach			Type	A1 Journal article
	Year	2016	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
	Volume	93	Issue	93	Pages	165112
	Keywords	A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT)
	Abstract	Simulations are carried out based on the dynamical mean-field theory (DMFT) in order to investigate the properties of correlated thin films for various values of the chemical potential, temperature, interaction strength, and applied transverse electric field. Application of a sufficiently strong field to a thin film at half filling leads to the appearance of conducting regions near the surfaces of the film, whereas in doped slabs the application of a field leads to a conductivity enhancement on one side of the film and a gradual transition to the insulating state on the opposite side. In addition to the inhomogeneous DMFT, a local density approximation (LDA) is considered in which the particle density n, quasiparticle residue Z, and spectral weight at the Fermi level A(ω=0) of each layer are approximated by a homogeneous bulk environment. A systematic comparison between the two approaches reveals that the less expensive LDA results are in good agreement with the DMFT approach, except close to the metal-to-insulator transition points and in the layers immediately at the film surfaces. LDA values for n are overall more reliable than those for Z and A(ω=0). The hysteretic behavior (memory effect) characteristic of the bulk doping driven Mott transition persists in the slab.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Lancaster, Pa	Editor
	Language		Wos	000373572700002	Publication Date	2016-04-09
	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	5	Open Access
	Notes	; This work was partially funded by the Flemish Fund for Scientific Research (FWO Belgium) under FWO Grant No. G.0520.10 and the joint FWF (Austria)-FWO Grant No. GOG6616N, and by the SITOGA FP7 project. Most of the calculations were performed on KU Leuven's ThinKing HPC cluster provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government-department EWI. ;			Approved	Most recent IF: 3.836
	Call Number	UA @ lucian @ c:irua:132872			Serial	4167
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	Author	Zhang, L.; Fernández Becerra, V.; Covaci, L.; Milošević, M.V.
	Title	Electronic properties of emergent topological defects in chiral p-wave superconductivity			Type	A1 Journal article
	Year	2016	Publication	Physical review B	Abbreviated Journal	Phys Rev B
	Volume	94	Issue	94	Pages	024520
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Chiral p-wave superconductors in applied magnetic field can exhibit more complex topological defects than just conventional superconducting vortices, due to the two-component order parameter (OP) and the broken time-reversal symmetry. We investigate the electronic properties of those exotic states, some of which contain clusters of one-component vortices in chiral components of the OP and/or exhibit skyrmionic character in the relative OP space, all obtained as a self-consistent solution of the microscopic Bogoliubov-de Gennes equations. We reveal the link between the local density of states (LDOS) of the novel topological states and the behavior of the chiral domain wall between the OP components, enabling direct identification of those states in scanning tunneling microscopy. For example, a skyrmion always contains a closed chiral domain wall, which is found to be mapped exactly by zero-bias peaks in LDOS. Moreover, the LDOS exhibits electron-hole asymmetry, which is different from the LDOS of conventional vortex states with same vorticity. Finally, we present the magnetic field and temperature dependence of the properties of a skyrmion, indicating that this topological defect can be surprisingly large in size, and can be pinned by an artificially indented nonsuperconducting closed path in the sample. These features are expected to facilitate the experimental observation of skyrmionic states, thereby enabling experimental verification of chirality in emerging superconducting materials.
	Address
	Corporate Author				Thesis
	Publisher	American Physical Society	Place of Publication	New York, N.Y	Editor
	Language		Wos	000381479500002	Publication Date	2016-07-26
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2469-9969	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	27	Open Access
	Notes	; This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO). ;			Approved	Most recent IF: 3.836
	Call Number	UA @ lucian @ c:irua:135742			Serial	4303
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	Author	Zhang, L.-F.; Flammia, L.; Covaci, L.; Perali, A.; Milošević, M.V.
	Title	Multifaceted impact of a surface step on superconductivity in atomically thin films			Type	A1 Journal article
	Year	2017	Publication	Physical review B	Abbreviated Journal	Phys Rev B
	Volume	96	Issue	10	Pages	104509
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Recent experiments show that an atomic step on the surface of atomically thin metallic films can strongly affect electronic transport. Here we reveal multiple and versatile effects that such a surface step can have on superconductivity in ultrathin films. By solving the Bogoliubov-de Gennes equations self-consistently in this regime, where quantum confinement dominates the emergent physics, we show that the electronic structure is profoundly modified on the two sides of the step, as is the spatial distribution of the superconducting order parameter and its dependence on temperature and electronic gating. Furthermore, the surface step changes nontrivially the transport properties both in the proximity-induced superconducting pair correlations and the Josephson effect, depending on the step height. These results offer a new route to tailor superconducting circuits and design atomically thin heterojunctions made of one same material.
	Address
	Corporate Author				Thesis
	Publisher	American Physical Society	Place of Publication	New York, N.Y	Editor
	Language		Wos	000411076000012	Publication Date	2017-09-18
	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	7	Open Access
	Notes	; This work was supported by the Research Foundation Flanders (FWO-Vlaanderen), the Special Research Funds of the University of Antwerp (TOPBOF project) and the Italian MIUR through the PRIN 2015 program (Contract No. 2015C5SEJJ001). ;			Approved	Most recent IF: 3.836
	Call Number	UA @ lucian @ c:irua:146750			Serial	4790
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	Author	Lane, T.L.M.; Andelkovic, M.; Wallbank, J.R.; Covaci, L.; Peeters, F.M.; Fal'ko, V.I.
	Title	Ballistic electron channels including weakly protected topological states in delaminated bilayer graphene			Type	A1 Journal article
	Year	2018	Publication	Physical review B	Abbreviated Journal	Phys Rev B
	Volume	97	Issue	4	Pages	045301
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	<script type='text/javascript'>document.write(unpmarked('We show that delaminations in bilayer graphene (BLG) with electrostatically induced interlayer symmetry can provide one with ballistic channels for electrons with energies inside the electrostatically induced BLG gap. These channels are formed by a combination of valley-polarized evanescent states propagating along the delamination edges (which persist in the presence of a strong magnetic field) and standing waves bouncing between them inside the delaminated region (in a strong magnetic field, these transform into Landau levels in the monolayers). For inverted stackings in BLGs on the left and right of the delamination (AB-2ML-BA or BA-2ML-AB, where 2ML indicates two decoupled monolayers of graphene), the lowest-energy ballistic channels are gapless, have linear dispersion, and appear to be weakly topologically protected. When BLG stackings on both sides of the delamination are the same (AB-2ML-AB or BA-2ML-BA), the lowest-energy ballistic channels are gapped, with a gap epsilon(g) scaling as epsilon(g) alpha W-1 with delamination width and epsilon(g) alpha delta(-1) with the on-layer energy difference in the delaminated part of the structure. Depending on the width, delaminations may also support several \u0022higher-energy\u0022 waveguide modes. Our results are based on both the analytical study of the wave matching of Dirac states and tight-binding model calculations, and we analyze in detail the dependence of the delamination spectrum on the electrostatic conditions in the structure, such as the vertical displacement field.'));
	Address
	Corporate Author				Thesis
	Publisher	American Physical Society	Place of Publication	New York, N.Y	Editor
	Language		Wos	000419772200005	Publication Date	2018-01-11
	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	11	Open Access
	Notes	; This work was funded by EPSRC via EPSRC Grand Engineering Chellenges Grant No. EP/N010345, the Manchester NOWNANO CDT EP/L-1548X, the Flemish Science Foundation (FWO-VI), the European Graphene Flagship project, ERC Synergy grant Hetero2D, and FLAG-ERA project TRANS2DTMD. The authors would like to acknowledge useful discussions with M. Zarenia, S. Slizovskiy, E. McCann, and K. Novesolov. ;			Approved	Most recent IF: 3.836
	Call Number	UA @ lucian @ c:irua:148441UA @ admin @ c:irua:148441			Serial	4868
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	Author	Zhang, L.-F.; Covaci, L.; Milošević, M.V.
	Title	Topological phase transitions in small mesoscopic chiral p-wave superconductors			Type	A1 Journal article
	Year	2017	Publication	Physical review B	Abbreviated Journal	Phys Rev B
	Volume	96	Issue	22	Pages	224512
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	<script type='text/javascript'>document.write(unpmarked('Spin-triplet chiral p-wave superconductivity is typically described by a two-component order parameter, and as such is prone to unique emergent effects when compared to the standard single-component superconductors. Here we present the equilibrium phase diagram for small mesoscopic chiral p-wave superconducting disks in the presence of magnetic field, obtained by solving the microscopic Bogoliubov-de Gennes equations self-consistently. In the ultrasmall limit, the cylindrically symmetric giant-vortex states form the ground state of the system. However, with increasing sample size, the cylindrical symmetry is broken as the two components of the order parameter segregate into domains, and the number of fragmented domain walls between them characterizes the resulting states. Such domain walls are topological defects unique for the p-wave order, and constitute a dominant phase in the mesoscopic regime. Moreover, we find two possible types of domain walls, identified by their chirality-dependent interaction with the edge states.'));
	Address
	Corporate Author				Thesis
	Publisher	American Physical Society	Place of Publication	New York, N.Y	Editor
	Language		Wos	000418653500012	Publication Date	2017-12-26
	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	18	Open Access
	Notes	; This work was supported by the Research Foundation Flanders (FWO-Vlaanderen) and the Special Research Funds of the University of Antwerp. ;			Approved	Most recent IF: 3.836
	Call Number	UA @ lucian @ c:irua:148504			Serial	4901
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	Author	Flammia, L.; Zhang, L.-F.; Covaci, L.; Perali, A.; Milošević, M.V.
	Title	Superconducting nanoribbon with a constriction : a quantum-confined Josephson junction			Type	A1 Journal article
	Year	2018	Publication	Physical review B	Abbreviated Journal	Phys Rev B
	Volume	97	Issue	13	Pages	134514
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Extended defects are known to strongly affect nanoscale superconductors. Here, we report the properties of superconducting nanoribbons with a constriction formed between two adjacent step edges by solving the Bogoliubov-de Gennes equations self-consistently in the regime where quantum confinement is important. Since the quantum resonances of the superconducting gap in the constricted area are different from the rest of the nanoribbon, such constriction forms a quantum-confined S-S'-S Josephson junction, with a broadly tunable performance depending on the length and width of the constriction with respect to the nanoribbon, and possible gating. These findings provide an intriguing approach to further tailor superconducting quantum devices where Josephson effect is of use.
	Address
	Corporate Author				Thesis
	Publisher	American Physical Society	Place of Publication	New York, N.Y	Editor
	Language		Wos	000430161500004	Publication Date	2018-04-17
	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	7	Open Access
	Notes	; This work was supported by the Research Foundation Flanders (FWO-Vlaanderen), the Special Research Funds of the University of Antwerp (TOPBOF), the Italian MIUR through the PRIN 2015 program (Contract No. 2015C5SEJJ001), the MultiSuper network, and the EU-COST NANOCOHYBRI action CA16218. ;			Approved	Most recent IF: 3.836
	Call Number	UA @ lucian @ c:irua:150754UA @ admin @ c:irua:150754			Serial	4980
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	Author	Pandey, T.; Covaci, L.; Milošević, M.V.; Peeters, F.M.
	Title	Flexoelectricity and transport properties of phosphorene nanoribbons under mechanical bending			Type	A1 Journal article
	Year	2021	Publication	Physical Review B	Abbreviated Journal	Phys Rev B
	Volume	103	Issue	23	Pages	235406
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We examine from first principles the flexoelectric properties of phosphorene nanoribbons under mechanical bending along armchair and zigzag directions. In both cases we find that the radial polarization depends linearly on the strain gradient. The flexoelectricity along the armchair direction is over 40% larger than along the zigzag direction. The obtained flexoelectric coefficients of phosphorene are four orders of magnitude larger than those of graphene and comparable to transition metal dichalcogenides. Analysis of charge density shows that the flexoelectricity mainly arises from the pz orbitals of phosphorus atoms. The electron mobilities in bent phosphorene can be enhanced by over 60% along the armchair direction, which is significantly higher than previous reports of mobility tuned by uniaxial strain. Our results indicate phosphorene is a candidate for a two-dimensional material applicable in flexible-electronic devices.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000657129800006	Publication Date	2021-06-02
	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	8	Open Access	Not_Open_Access
	Notes				Approved	Most recent IF: 3.836
	Call Number	UA @ admin @ c:irua:179109			Serial	6996
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	Author	Covaci, L.; Marsiglio, F.
	Title	Proximity effect and Josephson current in clean strong/weak/strong superconducting trilayers			Type	A1 Journal article
	Year	2006	Publication	Physical Review B	Abbreviated Journal	Phys Rev B
	Volume	73	Issue	1	Pages	014503
	Keywords	A1 Journal article
	Abstract	Recent measurements of the Josephson critical current through LSCO/LCO/LSCO thin films showed an unusually large proximity effect. Using the Bogoliubov-de Gennes equations for a tight-binding Hamiltonian we describe the proximity effect in weak links between a superconductor with critical temperature T-c and one with critical temperature T-c('), where T-c > T-c('). The weak link (N-') is therefore a superconductor above its own critical temperature and the superconducting regions are considered to have either s-wave or d-wave symmetry. We note that the proximity effect is enhanced due to the presence of superconducting correlations in the weak link. The dc Josephson current is calculated, and we obtain a nonzero value for temperatures greater than T-c(') for sizes of the weak links that can be almost an order of magnitude greater than the conventional coherence length. Considering pockets of superconductivity in the N-' layer, we show that this can lead to an even larger effect on the Josephson critical current by effectively shortening the weak link.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000235009000103	Publication Date	2006-01-03
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121	ISBN		Additional Links
	Impact Factor	3.836	Times cited	31	Open Access
	Notes				Approved	Most recent IF: 3.836; 2006 IF: 3.107
	Call Number	UA @ lucian @			Serial	4427
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	Author	Kim, W.; Covaci, L.; Marsiglio, F.
	Title	Impurity scattering of wave packets on a lattice			Type	A1 Journal article
	Year	2006	Publication	Physical Review B	Abbreviated Journal	Phys Rev B
	Volume	74	Issue	20	Pages	205120
	Keywords	A1 Journal article
	Abstract	Quantum transport in a lattice is distinct from its counterpart in continuum media. Even a free wave packet travels differently in a lattice than in the continuum. We describe quantum scattering in a one-dimensional lattice and illustrate characteristics of quantum transport such as resonant transmission. In particular we examine the transport characteristics of a random trimer model. We demonstrate the real-time propagation of a wave packet and its phase shift due to impurity configurations. Spin-flip scattering is also taken into account in a spin-chain system. We show how individual spins in the chain evolve as a result of a spin-flip interaction between an incoming electron and a spin chain.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000242409400030	Publication Date	2006-11-27
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121	ISBN		Additional Links
	Impact Factor	3.836	Times cited	14	Open Access
	Notes				Approved	Most recent IF: 3.836; 2006 IF: 3.107
	Call Number	UA @ lucian @			Serial	4428
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	Author	Kim, W.; Covaci, L.; Marsiglio, F.
	Title	Hidden symmetries of electronic transport in a disordered one-dimensional lattice			Type	A1 Journal article
	Year	2006	Publication	Physical Review B	Abbreviated Journal	Phys Rev B
	Volume	73	Issue	19	Pages	195109
	Keywords	A1 Journal article
	Abstract	Correlated, or extended, impurities play an important role in the transport properties of dirty metals. Here, we examine, in the framework of a tight-binding lattice, the transmission of a single electron through an array of correlated impurities. In particular we show that particles transmit through an impurity array in identical fashion, regardless of the direction of traversal. The demonstration of this fact is straightforward in the continuum limit, but requires a detailed proof for the discrete lattice. We also briefly demonstrate and discuss the time evolution of these scattering states, to delineate regions (in time and space) where the aforementioned symmetry is violated.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000237950400042	Publication Date	2006-05-11
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121	ISBN		Additional Links
	Impact Factor	3.836	Times cited	5	Open Access
	Notes				Approved	Most recent IF: 3.836; 2006 IF: 3.107
	Call Number	UA @ lucian @			Serial	4429
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	Author	Doğan, F.; Covaci, L.; Kim, W.; Marsiglio, F.
	Title	Emerging nonequilibrium bound state in spin-current–local-spin scattering			Type	A1 Journal article
	Year	2009	Publication	Physical Review B	Abbreviated Journal	Phys Rev B
	Volume	80	Issue	10	Pages	104434
	Keywords	A1 Journal article
	Abstract	Magnetization reversal is a well-studied problem with obvious applicability in computer hard drives. One can accomplish a magnetization reversal in at least one of two ways: application of a magnetic field or through a spin current. The latter is more amenable to a fully quantum-mechanical analysis. We formulate and solve the problem whereby a spin current interacts with a ferromagnetic Heisenberg spin chain, to eventually reverse the magnetization of the chain. Spin flips are accomplished through both elastic and inelastic scattering. A consequence of the inelastic-scattering channel, when it is no longer energetically possible, is the occurrence of a nonequilibrium bound state, which is an emergent property of the coupled local plus itinerant spin system. For certain definite parameter values the itinerant spin lingers near the local spins for some time, before eventually leaking out as an outwardly diffusing state. This phenomenon results in spin-flip dynamics and filtering properties for this type of system.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000270383100077	Publication Date	2009-09-25
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121	ISBN		Additional Links
	Impact Factor	3.836	Times cited		Open Access
	Notes				Approved	Most recent IF: 3.836; 2009 IF: 3.475
	Call Number	UA @ lucian @			Serial	4436
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	Author	Zha, G.-Q.; Covaci, L.; Zhou, S.-P.; Peeters, F.M.
	Title	Proximity-induced pseudogap in mesoscopic superconductor/normal-metal bilayers			Type	A1 Journal article
	Year	2010	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
	Volume	82	Issue	14	Pages	140502-140502,4
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Recent scanning tunneling microscopy (STM) measurements of the proximity effect in Au/La2−xSrxCuO4 and La1.55Sr0.45CuO4/La2−xSrxCuO4 bilayers showed a proximity-induced pseudogap [O. Yuli, I. Asulin, Y. Kalcheim, G. Koren, and O. Millo, Phys. Rev. Lett. 103, 197003 (2009)]. We describe the proximity effect in mesoscopic superconductor/normal-metal bilayers by using the Bogoliubov-de Gennes equations for a tight-binding Hamiltonian with competing antiferromagnetic and d-wave superconductivity orders. The temperature-dependent local density of states is calculated as a function of the distance from the interface. Bound state due to both d-wave and spin-density wave gaps are formed in the normal metal for energies less than the respective gaps. If there is a mismatch between the Fermi velocities in the two layers we observe that these states will shift in energy when spin-density wave order is present, thus inducing a minigap at finite energy. We conclude that the STM measurement in the proximity structures is able to distinguish between the two scenarios proposed for the pseudogap (competing or precursor to superconductivity).
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000282507200002	Publication Date	2010-10-05
	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	7	Open Access
	Notes	; This work was supported by the Flemish Science Foundation (FWO-Vl), by Belgian Science Policy (IAP), by National Natural Science Foundation of China under Grants No. 10904089 and No. 60971053, by the Research Fund of Higher Education of China under Grant No. 20093108120005, by Shanghai Leading Academic Discipline project under Grant No. S30105, by Science and Technology Committee of Shanghai Municipal under Grant No. 09JC1406000, by Shanghai Municipal Education Committee under Grants No. shu-08053 and No. 10zz63, and by Innovation Funds of Shanghai University. ;			Approved	Most recent IF: 3.836; 2010 IF: 3.774
	Call Number	UA @ lucian @ c:irua:85028			Serial	2735
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	Author	Chaves, A.; Covaci, L.; Rakhimov, K.Y.; Farias, G.A.; Peeters, F.M.
	Title	Wave-packet dynamics and valley filter in strained graphene			Type	A1 Journal article
	Year	2010	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
	Volume	82	Issue	20	Pages	205430
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The time evolution of a wave packet in strained graphene is studied within the tight-binding model and continuum model. The effect of an external magnetic field, as well as a strain-induced pseudomagnetic field, on the wave-packet trajectories and zitterbewegung are analyzed. Combining the effects of strain with those of an external magnetic field produces an effective magnetic field which is large in one of the Dirac cones, but can be practically zero in the other. We construct an efficient valley filter, where for a propagating incoming wave packet consisting of momenta around the K and K' Dirac points, the outgoing wave packet exhibits momenta in only one of these Dirac points while the components of the packet that belong to the other Dirac point are reflected due to the Lorentz force. We also found that the zitterbewegung is permanent in time in the presence of either external or strain-induced magnetic fields, but when both the external and strain-induced magnetic fields are present, the zitterbewegung is transient in one of the Dirac cones, whereas in the other cone the wave packet exhibits permanent spatial oscillations.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000284401600007	Publication Date	2010-11-19
	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	95	Open Access
	Notes	; This work was financially supported by CNPq under NanoBioEstruturas Contract No. 555183/2005-0, PRONEX/CNPq/FUNCAP, CAPES, the Bilateral program between Flanders and Brazil, the Belgian Science Policy (IAP), and the Flemish Science Foundation (FWO-V1) ;			Approved	Most recent IF: 3.836; 2010 IF: 3.774
	Call Number	UA @ lucian @ c:irua:95542			Serial	3905
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	Author	Li, Z.; Covaci, L.; Berciu, M.; Baillie, D.; Marsiglio, F.
	Title	Impact of spin-orbit coupling on the Holstein polaron			Type	A1 Journal article
	Year	2011	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
	Volume	83	Issue	19	Pages	195104-195104,9
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We utilize an exact variational numerical procedure to calculate the ground state properties of a polaron in the presence of a Rashba-like spin-orbit interaction. Our results corroborate previous work performed with the momentum average approximation and with weak-coupling perturbation theory. We find that spin-orbit coupling increases the effective mass in the regime with weak electron-phonon coupling, and decreases the effective mass in the regimes of intermediate and strong electron-phonon coupling. Analytical strong-coupling perturbation theory results confirm our numerical results in the small-polaron regime. A large amount of spin-orbit coupling can lead to a significant lowering of the polaron effective mass.
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	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000290162500001	Publication Date	2011-05-03
	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	9	Open Access
	Notes	; This work was supported in part by the Natural Sciences and Engineering Research Council of Canada (NSERC), by ICORE (Alberta), by Alberta Ingenuity, by the Flemish Science Foundation (FWO-Vl), and by the Canadian Institute for Advanced Research (CIfAR). ;			Approved	Most recent IF: 3.836; 2011 IF: 3.691
	Call Number	UA @ lucian @ c:irua:89718			Serial	1561
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	Author	Covaci, L.; Peeters, F.M.
	Title	Superconducting proximity effect in graphene under inhomogeneous strain			Type	A1 Journal article
	Year	2011	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
	Volume	84	Issue	24	Pages	241401-241401,4
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The interplay between quantum Hall states and Cooper pairs is usually hindered by the suppression of the superconducting state due to the strong magnetic fields needed to observe the quantum Hall effect. From this point of view, graphene is special since it allows the creation of strong pseudomagnetic fields due to strain. We show that in a Josephson junction made of strained graphene, Cooper pairs will diffuse into the strained region. The pair correlation function will be sublattice polarized due to the polarization of the local density of states in the zero pseudo-Landau level. We uncover two regimes: (1) one in which the cyclotron radius is larger than the junction length, in which case the supercurrent will be enhanced, and (2) the long junction regime where the supercurrent is strongly suppressed because the junction becomes an insulator. In the latter case quantized Hall states form and Andreev scattering at the normal/superconducting interface will induce edge states. Our numerical calculation has become possible due to an extension of the Chebyshev-Bogoliubovde Gennes method to computations on video cards (GPUs).
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	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000297766600003	Publication Date	2011-12-06
	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	27	Open Access
	Notes	; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Euro GRAPHENE project CONGRAN. Discussions with Andrey Chaves are gratefully acknowledged. ;			Approved	Most recent IF: 3.836; 2011 IF: 3.691
	Call Number	UA @ lucian @ c:irua:93962			Serial	3364
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