toggle visibility
Search within Results:
Display Options:

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Komendová, L.; Milošević, M.V.; Shanenko, A.A.; Peeters, F.M. url  doi
openurl 
  Title Different length scales for order parameters in two-gap superconductors : extended Ginzburg-Landau theory Type A1 Journal article
  Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 84 Issue 6 Pages (down) 064522-064522,5  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Using the Ginzburg-Landau theory extended to the next-to-leading order, we determine numerically the healing lengths of the two order parameters at the two-gap superconductor/normal metal interface. We demonstrate on several examples that those can be different even in the strict domain of applicability of the Ginzburg-Landau theory. This justifies the use of this theory to describe relevant physics of two-gap superconductors, distinguishing them from their single-gap counterparts. The calculational degree of complexity increases only slightly with respect to the conventional Ginzburg-Landau expansion, thus the extended Ginzburg-Landau model remains numerically far less demanding compared to the full microscopic approaches.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000294226000013 Publication Date 2011-08-25  
  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 56 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the ESF-INSTANS network. ; Approved Most recent IF: 3.836; 2011 IF: 3.691  
  Call Number UA @ lucian @ c:irua:92414 Serial 695  
Permanent link to this record
 

 
Author Zha, G.-Q.; Chen, Y.; Peeters, F.M.; Zhou, S.-P. url  doi
openurl 
  Title Impurity-induced modulations of orders in d-wave superconductors Type A1 Journal article
  Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B  
  Volume 80 Issue 6 Pages (down) 064518,1-064518,5  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract By using a model Hamiltonian with competing antiferromagnetic (AFM) and d-wave superconductivity orders, the impurity-induced structures of orders in d-wave superconductors is investigated. We find that the transition between one-dimensional stripe and two-dimensional checkerboardlike modulation around a single nonmagnetic impurity can take place as the strength of the AFM interaction U or the impurity scattering strength V0 is varied. It is also found that the impurity-induced stripe can first transit to checkerboardlike modulation and then disappears with increasing the next-nearest-neighbor hopping strength |t|. Phase diagrams of V0 versus U and |t| for various modulations of the spin order are presented. In addition, the quantum interference effect on the modulations of orders due to two strong nonmagnetic impurities is briefly examined, and the checkerboardlike and quasistripe patterns can occur depending on the sites where two impurities are placed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000269638800074 Publication Date 2009-09-01  
  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 3 Open Access  
  Notes Approved Most recent IF: 3.836; 2009 IF: 3.475  
  Call Number UA @ lucian @ c:irua:78293 Serial 1572  
Permanent link to this record
 

 
Author Lozano, D.P.; Couet, S.; Petermann, C.; Hamoir, G.; Jochum, J.K.; Picot, T.; Menendez, E.; Houben, K.; Joly, V.; Antohe, V.A.; Hu, M.Y.; Leu, B.M.; Alatas, A.; Said, A.H.; Roelants, S.; Partoens, B.; Milošević, M.V.; Peeters, F.M.; Piraux, L.; Van de Vondel, J.; Vantomme, A.; Temst, K.; Van Bael, M.J. url  doi
openurl 
  Title Experimental observation of electron-phonon coupling enhancement in Sn nanowires caused by phonon confinement effects Type A1 Journal article
  Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 99 Issue 6 Pages (down) 064512  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Reducing the size of a superconductor below its characteristic length scales can either enhance or suppress its critical temperature (T-c). Depending on the bulk value of the electron-phonon coupling strength, electronic and phonon confinement effects will play different roles in the modification of T-c. Experimentally disentangling each contribution has remained a challenge. We have measured both the phonon density of states and T-c of Sn nanowires with diameters of 18, 35, and 100 nm in order to quantify the effects of phonon confinement on superconductivity. We observe a shift of the phonon frequency towards the low-energy region and an increase in the electron-phonon coupling constant that can account for the measured increase in T-c.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000459322400005 Publication Date 2019-02-21  
  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 would like to thanks Jeroen Scheerder and Wout Keijers for their help and assistance during the low-temperature measurements. This work was supported by the Research Foundation Flanders (FWO), the Concerted Research Action (GOA/14/ 007), the Federation Wallonie-Bruxelles (ARC 13/18-052, Supracryst) and the Fonds de la Recherche Scientifique -FNRS under Grant No. T.0006.16. The authors acknowledge Hercules Stichting (Project Nos. AKUL/13/19 and AKUL/13/25). D.P.L. thanks the FWO for financial support. This research used resources of the Advanced Photon Source, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. ; Approved Most recent IF: 3.836  
  Call Number UA @ admin @ c:irua:158621 Serial 5212  
Permanent link to this record
 

 
Author Berdiyorov, G.R.; Yu, S.H.; Xiao, Z.L.; Peeters, F.M.; Hua, J.; Imre, A.; Kwok, W.K. url  doi
openurl 
  Title Effect of sample geometry on the phase boundary of a mesoscopic superconducting loop Type A1 Journal article
  Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B  
  Volume 80 Issue 6 Pages (down) 064511,1-064511,6  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We studied the effect of sample geometry on the evolution of the superconducting state in nanoscale Nb circular and square loops by transport measurements. A multistage resistive transition with temperature is found for both samples, which is related to the effect of contact leads made from the same superconducting material. The H-T phase diagrams close to Tc0 show clear periodic oscillations on top of a parabolic background, i.e., Little-Parks effect. However, the amplitude of the oscillations decreases faster in the circular loop compared to the one in the square sample. Numerical simulations are conducted within the nonlinear Ginzburg-Landau theory to show the effect of sample geometry on the nucleation of superconductivity in superconducting loop structures.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000269638800067 Publication Date 2009-08-17  
  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 21 Open Access  
  Notes Approved Most recent IF: 3.836; 2009 IF: 3.475  
  Call Number UA @ lucian @ c:irua:78292 Serial 833  
Permanent link to this record
 

 
Author Saniz, R.; Partoens, B.; Peeters, F.M. url  doi
openurl 
  Title Confinement effects on electron and phonon degrees of freedom in nanofilm superconductors : a Green function approach Type A1 Journal article
  Year 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 87 Issue 6 Pages (down) 064510-64513  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The Green function approach to the Bardeen-Cooper-Schrieffer theory of superconductivity is used to study nanofilms. We go beyond previous models and include effects of confinement on the strength of the electron-phonon coupling as well as on the electronic spectrum and on the phonon modes. Within our approach, we find that in ultrathin films, confinement effects on the electronic screening become very important. Indeed, contrary to what has been advanced in recent years, the sudden increases of the density of states when new bands start to be occupied as the film thickness increases, tend to suppress the critical temperature rather than to enhance it. On the other hand, the increase of the number of phonon modes with increasing number of monolayers in the film leads to an increase in the critical temperature. As a consequence, the superconducting critical parameters in such nanofilms are determined by these two competing effects. Furthermore, in sufficiently thin films, the condensate consists of well-defined subcondensates associated with the occupied bands, each with a distinct coherence length. The subcondensates can interfere constructively or destructively giving rise to an interference pattern in the Cooper pair probability density.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000315374100009 Publication Date 2013-02-25  
  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 ; This work was supported by the Flemish Science Foundation (FWO-Vl). R.S. thanks M. R. Norman, B. Soree, and L. Komendova for useful comments. ; Approved Most recent IF: 3.836; 2013 IF: 3.664  
  Call Number UA @ lucian @ c:irua:107072 Serial 487  
Permanent link to this record
 

 
Author Baelus, B.J.; Cabral, L.R.E.; Peeters, F.M. url  doi
openurl 
  Title Vortex shells in mesoscopic superconducting disks Type A1 Journal article
  Year 2004 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 69 Issue Pages (down) 064506,1-12  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000220092100067 Publication Date 2004-02-21  
  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 94 Open Access  
  Notes Approved Most recent IF: 3.836; 2004 IF: 3.075  
  Call Number UA @ lucian @ c:irua:69381 Serial 3883  
Permanent link to this record
 

 
Author Doria, M.M.; Romaguera, A.R. de C.; Peeters, F.M. url  doi
openurl 
  Title Effect of the boundary condition on the vortex patterns in mesoscopic three-dimensional superconductors: disk and sphere Type A1 Journal article
  Year 2007 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 75 Issue 6 Pages (down) 064505,1-6  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000244533000072 Publication Date 2007-02-14  
  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 37 Open Access  
  Notes Approved Most recent IF: 3.836; 2007 IF: 3.172  
  Call Number UA @ lucian @ c:irua:63791 Serial 844  
Permanent link to this record
 

 
Author Zhao, H.-W.; Zha, G.-Q.; Zhou, S.-P.; Peeters, F.M. url  doi
openurl 
  Title Long-range Coulomb repulsion effect on a charged vortex in high-temperature superconductors with competing d-wave and antiferromagnetic orders Type A1 Journal article
  Year 2008 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B  
  Volume 78 Issue 6 Pages (down) 064505,1-064505,5  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Vortex charges in high-temperature superconductor (HTS) are studied by solving the Bogoliubovde Gennes equations based on a model Hamiltonian with antiferromagnetic (AF) and d-wave orders in the presence of the long-range Coulomb repulsion. For a sufficient strength of the AF order, the negative vortex charge is found. A sign change between negative and positive may occur by tuning the long-range Coulomb repulsion strength or the doping parameter. Recent NMR experiments are hopefully understood. We show that the charged vortex can induce a spin-orbit coupling that is important for superconductors with a short coherence length and a large value of the energy gap over the Fermi-level ratio. Fractional flux quanta are possible for HTS.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000259264900084 Publication Date 2008-08-06  
  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 12 Open Access  
  Notes Approved Most recent IF: 3.836; 2008 IF: 3.322  
  Call Number UA @ lucian @ c:irua:76553 Serial 1837  
Permanent link to this record
 

 
Author Holden, T.; Habermeier, H.-U.; Cristiani, G.; Golnik, A.; Boris, A.; Pimenov, A.; Humlicek, J.; Lebedev, O.I.; Van Tendeloo, G.; Keimer, B.; Bernhard, C. doi  openurl
  Title Proximity induced metal-insulator transition in YBa2Cu3O7/La2/3Ca1/3MnO3 superlattices Type A1 Journal article
  Year 2004 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 69 Issue 6 Pages (down) 064505,1-064505,7  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The far-infrared dielectric response of superlattices (SL) composed of superconducting YBa2Cu3O7 (YBCO) and ferromagnetic La0.67Ca0.33MnO3 (LCMO) has been investigated by ellipsometry. A drastic decrease of the free-carrier response is observed which involves an unusually large length scale of d(crit)approximate to20 nm in YBCO and d(crit)approximate to10 nm in LCMO. A corresponding suppression of metallicity is not observed in SL's where LCMO is replaced by the paramagnetic metal LaNiO3. Our data suggest that either a long-range charge transfer from the YBCO to the LCMO layers or alternatively a strong coupling of the charge carriers to the different and competitive kind of magnetic correlations in the LCMO and YBCO layers is at the heart of the observed metal-insulator transition. The low free-carrier response observed in the far-infrared dielectric response of the magnetic superconductor RuSr2GdCu2O8 is possibly related to this effect.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000220092100066 Publication Date 2004-02-21  
  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 101 Open Access  
  Notes Approved Most recent IF: 3.836; 2004 IF: 3.075  
  Call Number UA @ lucian @ c:irua:54743 Serial 2734  
Permanent link to this record
 

 
Author Xu, B.; Milošević, M.V.; Peeters, F.M. url  doi
openurl 
  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 (down) 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  
Permanent link to this record
 

 
Author Zhang, L.; Zhang, Y.-Y.; Zha, G.-Q.; Milošević, M.V.; Zhou, S.-P. url  doi
openurl 
  Title Skyrmionic chains and lattices in s plus id superconductors Type A1 Journal article
  Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B  
  Volume 101 Issue 6 Pages (down) 064501  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We report characteristic vortex configurations in s + id superconductors with time-reversal symmetry breaking, exposed to magnetic field. A vortex in the s + id state tends to have an opposite phase winding between s- and d-wave condensates. We find that this peculiar feature together with the competition between s- and d-wave symmetry results in three distinct classes of vortical configurations. When either s or d condensate absolutely dominates, vortices form a conventional lattice. However, when one condensate is relatively dominant, vortices organize in chains that exhibit skyrmionic character, separating the chiral components of the s +/- id order parameter into domains within and outside the chain. Such skyrmionic chains are found stable even at high magnetic field. When s and d condensates have comparable strength, vortices split cores in two chiral components to form full-fledged skyrmions, i.e., coreless topological structures with an integer topological charge, organized in a lattice. We provide characteristic magnetic field distributions of all states, enabling their identification in, e.g., scanning Hall probe and scanning SQUID experiments. These unique vortex states are relevant for high-T-c cuprate and iron-based superconductors, where the relative strength of competing pairing symmetries is expected to be tuned by temperature and/or doping level, and can help distinguish s + is and s + id superconducting phases.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000510745600005 Publication Date 2020-02-03  
  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 7 Open Access  
  Notes ; The authors acknowledge useful discussions with Yong-Ping Zhang. This research was supported by the National Natural Science Foundation of China under Grants No. 61571277 and No. 61771298. L.-F.Z. and M.V.M. acknowledge support from Research Foundation-Flanders (FWO-Vlaanderen). ; Approved Most recent IF: 3.7; 2020 IF: 3.836  
  Call Number UA @ admin @ c:irua:166507 Serial 6605  
Permanent link to this record
 

 
Author Tsirlin, A.A.; Abakumov, A.M.; Ritter, C.; Rosner, H. url  doi
openurl 
  Title (CuCl)LaTa2O\text{7} and quantum phase transition in the (CuX)LaM2O7 family (X=Cl, Br; M=Nb, Ta) Type A1 Journal article
  Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 86 Issue 6 Pages (down) 064440-12  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract We apply neutron diffraction, high-resolution synchrotron x-ray diffraction, magnetization measurements, electronic structure calculations, and quantum Monte-Carlo simulations to unravel the structure and magnetism of (CuCl)LaTa2O7. Despite the pseudo-tetragonal crystallographic unit cell, this compound features an orthorhombic superstructure, similar to the Nb-containing (CuX)LaNb2O7 with X = Cl and Br. The spin lattice entails dimers formed by the antiferromagnetic fourth-neighbor coupling J(4), as well as a large number of nonequivalent interdimer couplings quantified by an effective exchange parameter J(eff). In (CuCl)LaTa2O7, the interdimer couplings are sufficiently strong to induce the long-range magnetic order with the Neel temperature T-N similar or equal to 7 K and the ordered magnetic moment of 0.53 mu(B), as measured with neutron diffraction. This magnetic behavior can be accounted for by J(eff)/J(4) similar or equal to 1.6 and J(4) similar or equal to 16 K. We further propose a general magnetic phase diagram for the (CuCl)LaNb2O7-type compounds, and explain the transition from the gapped spin-singlet (dimer) ground state in (CuCl)LaNb2O7 to the long-range antiferromagnetic order in (CuCl)LaTa2O7 and (CuBr)LaNb2O7 by an increase in the magnitude of the interdimer couplings J(eff)/J(4), with the (CuCl)LaM2O7 (M = Nb, Ta) compounds lying on different sides of the quantum critical point that separates the singlet and long-range-ordered magnetic ground states.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000308127600006 Publication Date 2012-08-29  
  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 Approved Most recent IF: 3.836; 2012 IF: 3.767  
  Call Number UA @ lucian @ c:irua:101886 Serial 3526  
Permanent link to this record
 

 
Author Mulkers, J.; Hals, K.M.D.; Leliaert, J.; Milošević, M.V.; Van Waeyenberge, B.; Everschor-Sitte, K. url  doi
openurl 
  Title Effect of boundary-induced chirality on magnetic textures in thin films Type A1 Journal article
  Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 98 Issue 6 Pages (down) 064429  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract In the quest for miniaturizing magnetic devices, the effects of boundaries and surfaces become increasingly important. Here we show how the recently predicted boundary-induced Dzyaloshinskii-Moriya interaction (DMI) affects the magnetization of ferromagnetic films with a C-infinity v symmetry and a perpendicular magnetic anisotropy. For an otherwise uniformly magnetized film, we find a surface twist when the magnetization in the bulk is canted by an in-plane external field. This twist at the surfaces caused by the boundary-induced DMI differs from the common canting caused by internal DMI observed at the edges of a chiral magnet. Furthermore, we find that the surface twist due to the boundary-induced DMI strongly affects the width of the domain wall at the surfaces. We also find that the skyrmion radius increases in the depth of the film, with the average size of the skyrmion increasing with boundary-induced DMI. This increase suggests that the boundary-induced DMI contributes to the stability of the skyrmion.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000443394600004 Publication Date 2018-08-31  
  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 9 Open Access  
  Notes ; The authors thank Matthias Sitte and Andre Thiaville for fruitful discussions. This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vlaanderen) through Project No. G098917N and the German Research Foundation (DFG) under the Project No. EV 196/2-1. J.L. is supported by the Ghent University Special Research Fund with a BOF postdoctoral fellowship. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:153706UA @ admin @ c:irua:153706 Serial 5093  
Permanent link to this record
 

 
Author Nikolaev, A.V.; Michel, K.H. url  doi
openurl 
  Title Superexchange and electron correlations in alkali fullerides AC60, A=K, Rb, Cs Type A1 Journal article
  Year 2005 Publication The journal of chemical physics Abbreviated Journal J Chem Phys  
  Volume 122 Issue 6 Pages (down) 064310-64314  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Superexchange interactions in alkali fullerides AC(60) are derived for C-60 molecular ions separated by interstitial alkali-metal ions. We use a multiconfiguration approach which comprises the lowest molecular orbital states of the C-60 molecule and the excited s and d states of the alkali-metal atom A. Interactions are described by the valence bond (Heitler-London) method for a complex (C-60 – A – C-60) – with two valence electrons. The electronic charge transfer between the alkali-metal atom and a neighboring C-60 molecule is not complete. The occupation probability of excited d and s states of the alkali atom is not negligible. In correspondence with the relative positions of the C-60 molecules and A atoms in the polymer crystal, we consider 180degrees and 90degrees (angle) superexchange pathways. For the former case the ground state is found to be a spin singlet separated from a triplet at similar to20 K. For T < 20 K there appear strong spin correlations for the 180degrees superexchange pathway. The results are related to spin lattice relaxation experiments on CsC60 in the polymerized and in the quenched cubic phase. (C) 2005 American Institute of Physics.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000226918100018 Publication Date 2005-02-02  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-9606; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.965 Times cited 11 Open Access  
  Notes Approved Most recent IF: 2.965; 2005 IF: 3.138  
  Call Number UA @ lucian @ c:irua:102740 Serial 3377  
Permanent link to this record
 

 
Author Michel, K.H.; Verberck, B.; Hulman, M.; Kuzmany, H.; Krause, M. doi  openurl
  Title Superposition of quantum and classical rotational motions in Sc2C2@C84 fullerite Type A1 Journal article
  Year 2007 Publication The journal of chemical physics Abbreviated Journal J Chem Phys  
  Volume 126 Issue 6 Pages (down) 064304,1-15  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000244250200008 Publication Date 2007-02-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-9606; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.965 Times cited 14 Open Access  
  Notes Approved Most recent IF: 2.965; 2007 IF: 3.044  
  Call Number UA @ lucian @ c:irua:63628 Serial 3381  
Permanent link to this record
 

 
Author Topalovic, D.B.; Arsoski, V.V.; Tadic, M.Z.; Peeters, F.M. pdf  doi
openurl 
  Title Asymmetric versus symmetric HgTe/CdxHg1-x Te double quantum wells: Bandgap tuning without electric field Type A1 Journal article
  Year 2020 Publication Journal Of Applied Physics Abbreviated Journal J Appl Phys  
  Volume 128 Issue 6 Pages (down) 064301-64308  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We investigate the electron states in double asymmetric HgTe / Cd x Hg 1 – x Te quantum wells grown along the [ 001 ] direction. The subbands are computed by means of the envelope function approximation applied to the eight-band Kane k . mml:mspace width=“.1em”mml:mspace p model. The asymmetry of the confining potential of the double quantum wells results in a gap opening, which is absent in the symmetric system where it can only be induced by an applied electric field. The bandgap and the subbands are affected by spin-orbit coupling, which is a consequence of the asymmetry of the confining potential. The electron-like and hole-like states are mainly confined in different quantum wells, and the enhanced hybridization between them opens a spin-dependent hybridization gap at a finite in-plane wavevector. We show that both the ratio of the widths of the two quantum wells and the mole fraction of the C d x H g 1 – x Te barrier control both the energy gap between the hole-like states and the hybridization gap. The energy subbands are shown to exhibit inverted ordering, and therefore, a nontrivial topological phase could emerge in the system.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000561339300001 Publication Date 2020-08-10  
  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 3 Open Access  
  Notes ; This research was funded by the Ministry of Education, Science and Technological Development of the Republic of Serbia and the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 3.2; 2020 IF: 2.068  
  Call Number UA @ admin @ c:irua:171146 Serial 6453  
Permanent link to this record
 

 
Author Galvan-Moya; Misko, V.R.; Peeters, F.M. url  doi
openurl 
  Title Chainlike transitions in Wigner crystals : sequential versus nonsequential Type A1 Journal article
  Year 2015 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 92 Issue 92 Pages (down) 064112  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The structural transitions of the ground state of a system of repulsively interacting particles confined in a quasi-one-dimensional channel, and the effect of the interparticle interaction as well as the functional form of the confinement potential on those transitions are investigated. Although the nonsequential ordering of transitions (non-SOT), i.e., the 1 – 2 – 4 – 3 – 4 – 5 – 6 – ... sequence of chain configurations with increasing density, is widely robust as predicted in a number of theoretical studies, the sequential ordering of transitions (SOT), i.e., the 1 – 2 – 3 – 4 – 5 – 6 – ... chain, is found as the ground state for long-ranged interparticle interaction and hard-wall-like confinement potentials. We found an energy barrier between every two different phases around its transition point, which plays an important role in the preference of the system to follow either a SOT or a non-SOT. However, that preferential transition requires also the stability of the phases during the transition. Additionally, we analyze the effect of a small structural disorder on the transition between the two phases around its transition point. Our results show that a small deformation of the triangular structure changes dramatically the picture of the transition between two phases, removing in a considerable region the non-SOT in the system. This feature could explain the fact that the non-SOT is, up to now, not observed in experimental systems, and suggests a more advanced experimental setup to detect the non-SOT.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000359859400003 Publication Date 2015-08-21  
  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 3 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Odysseus and Methusalem programmes of the Flemish government. Computational resources were provided by HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC). ; Approved Most recent IF: 3.836; 2015 IF: 3.736  
  Call Number UA @ lucian @ c:irua:127753 Serial 4148  
Permanent link to this record
 

 
Author Leys, F.E.; March, N.H.; Lamoen, D. doi  openurl
  Title High pressure limiting forms of the zero-temperature equations of state of Ta and Pu from relativistic Thomas-Fermi theory Type A1 Journal article
  Year 2003 Publication Physical Review B Abbreviated Journal Phys Rev B  
  Volume 67 Issue Pages (down) 064109  
  Keywords A1 Journal article; Electron Microscopy for Materials Science (EMAT);  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000181501100021 Publication Date 2003-03-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 1 Open Access  
  Notes Approved Most recent IF: 3.836; 2003 IF: NA  
  Call Number UA @ lucian @ c:irua:45628 Serial 1439  
Permanent link to this record
 

 
Author Gou, H.; Tsirlin, A.A.; Bykova, E.; Abakumov, A.M.; Van Tendeloo, G.; Richter, A.; Ovsyannikov, S.V.; Kurnosov, A.V.; Trots, D.M.; Konôpková, Z.; Liermann, H.P.; Dubrovinsky, L.; Dubrovinskaia, N.; url  doi
openurl 
  Title Peierls distortion, magnetism, and high hardness of manganese tetraboride Type A1 Journal article
  Year 2014 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 89 Issue 6 Pages (down) 064108-64109  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract We report crystal structure, electronic structure, and magnetism of manganese tetraboride, MnB4, synthesized under high-pressure, high-temperature conditions. In contrast to superconducting FeB4 and metallic CrB4, which are both orthorhombic, MnB4 features a monoclinic crystal structure. Its lower symmetry originates from a Peierls distortion of the Mn chains. This distortion nearly opens the gap at the Fermi level, but despite the strong dimerization and the proximity of MnB4 to the insulating state, we find indications for a sizable paramagnetic effective moment of about 1.7 mu(B)/f.u., ferromagnetic spin correlations, and, even more surprisingly, a prominent electronic contribution to the specific heat. However, no magnetic order has been observed in standard thermodynamic measurements down to 2 K. Altogether, this renders MnB4 a structurally simple but microscopically enigmatic material; we argue that its properties may be influenced by electronic correlations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000332405000002 Publication Date 2014-02-24  
  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 39 Open Access  
  Notes Approved Most recent IF: 3.836; 2014 IF: 3.736  
  Call Number UA @ lucian @ c:irua:115819 Serial 2571  
Permanent link to this record
 

 
Author Wang, W.; Van Duppen, B.; Van der Donck, M.; Peeters, F.M. url  doi
openurl 
  Title Magnetopolaron effect on shallow-impurity states in the presence of magnetic and intense terahertz laser fields in the Faraday configuration Type A1 Journal article
  Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 97 Issue 6 Pages (down) 064108  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The magnetopolaron effect on shallow-impurity states in semiconductors is investigated when subjected simultaneously to a magnetic field and an intense terahertz laser field within the Faraday configuration. We use a time-dependent nonperturbative theory to describe electron interactions. The externally applied fields are exactly included via a laser-dressed interaction potential. Through a variational approach we evaluate the binding energy of the shallow-impurity states. We find that the interaction strength of the laser-dressed Coulomb potential can not only be enhanced but also weakened by varying the two external fields. In this way, the binding energy can be tuned by the external fields and red-or blue-shifted with respect to the static binding energy. In the nonresonant polaron region, a magnetopolaron correction that includes the effects of photon process is observed. In the resonant polaron region, moreover, the resonant magnetopolaron effect accompanied by the emission and absorption of a single photon is distinctly observed. This can be modulated to be far away from the reststrahlen band. The intriguing findings of this paper can be observed experimentally and, in turn, provide a way to measure the strength of the electron-phonon interaction.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000426041900004 Publication Date 2018-02-26  
  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 9 Open Access  
  Notes ; This work was supported by the National Natural Science Foundation of China (Grants No. 11404214 and No. 11455015) and the China Scholarship Council (CSC), Anhui Provincial Natural Science Foundation (Grant No. 1408085QA13), Key Projects of Anhui Provincial Department of Education (Grants No. KJ2017A406 and No. KJ2017A401). B.V.D. was financially supported by the Research Science Foundation-Flanders (FWO-Vl) through a postdoctoral fellowship and M.V.d.D. was financially supported by the Research Science Foundation-Flanders (FWO-Vl) through a doctoral fellowship. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:149906UA @ admin @ c:irua:149906 Serial 4942  
Permanent link to this record
 

 
Author Wang, J.; Andelkovic, M.; Wang, G.; Peeters, F.M. url  doi
openurl 
  Title Molecular collapse in graphene: Sublattice symmetry effect Type A1 Journal article
  Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B  
  Volume 102 Issue 6 Pages (down) 064108-8  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Atomic collapse can be observed in graphene because of its large “effective” fine structure constant, which enables this phenomenon to occur for an impurity charge as low as Z(c) similar to 1-2. Here we investigate the effect of the sublattice symmetry on molecular collapse in two spatially separated charge tunable vacancies, which are located on the same (A-A type) or different (A-B type) sublattices. We find that the broken sublattice symmetry: (1) does not affect the location of the main bonding and antibonding molecular collapse peaks, (2) but shifts the position of the satellite peaks, because they are a consequence of the breaking of the local sublattice symmetry, and (3) there are vacancy characteristic collapse peaks that only occur for A-B type vacancies, which can be employed to distinguish them experimentally from the A-A type. As the charge, energy, and separation distance increase, the additional collapse features merge with the main molecular collapse peaks. We show that the spatial distribution around the vacancy site of the collapse states allows us to differentiate the molecular from the frustrated collapse.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000562320700002 Publication Date 2020-08-25  
  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 1 Open Access  
  Notes ; This work was supported by the National Natural Science Foundation of China (Grants No. 61874038 and No. 61704040), National Key R&D Program Grant 2018YFE0120000, the scholarship from China Scholarship Council (CSC: 201908330548), and TRANS2DTMD FlagEra project. ; Approved Most recent IF: 3.7; 2020 IF: 3.836  
  Call Number UA @ admin @ c:irua:172065 Serial 6562  
Permanent link to this record
 

 
Author Van Aert, S.; de Backer, A.; Martinez, G.T.; Goris, B.; Bals, S.; Van Tendeloo, G.; Rosenauer, A. url  doi
openurl 
  Title Procedure to count atoms with trustworthy single-atom sensitivity Type A1 Journal article
  Year 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 87 Issue 6 Pages (down) 064107-6  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract We report a method to reliably count the number of atoms from high-angle annular dark field scanning transmission electron microscopy images. A model-based analysis of the experimental images is used to measure scattering cross sections at the atomic level. The high sensitivity of these measurements in combination with a thorough statistical analysis enables us to count atoms with single-atom sensitivity. The validity of the results is confirmed by means of detailed image simulations. We will show that the method can be applied to nanocrystals of arbitrary shape, size, and atom type without the need for a priori knowledge about the atomic structure.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000315144700006 Publication Date 2013-02-20  
  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 106 Open Access  
  Notes FWO; 262348 ESMI; 312483 ESTEEM2;246791 COUNTATOMS; Hercules 3; esteem2_jra2 Approved Most recent IF: 3.836; 2013 IF: 3.664  
  Call Number UA @ lucian @ c:irua:105674 Serial 2718  
Permanent link to this record
 

 
Author Satarifard, V.; Mousaei, M.; Hadadi, F.; Dix, J.; Sobrino Fernández, M.; Carbone, P.; Beheshtian, J.; Peeters, F.M.; Neek-Amal, M. url  doi
openurl 
  Title Reversible structural transition in nanoconfined ice Type A1 Journal article
  Year 2017 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 95 Issue 95 Pages (down) 064105  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The report on square ice sandwiched between two graphene layers by Algara-Siller et al. [Nature (London) 519, 443 (2015)] has generated a large interest in this system. By applying high lateral pressure on nanoconfined water, we found that monolayer ice is transformed to bilayer ice when the two graphene layers are separated by H = 6,7 angstrom. It was also found that three layers of a denser phase of ice with smaller lattice constant are formed if we start from bilayer ice and apply a lateral pressure of about 0.7 GPa with H = 8,9 angstrom. The lattice constant (2.5-2.6 angstrom) in both transitions is found to be smaller than those typical for the known phases of ice and water, i.e., 2.8 angstrom. We validate these results using ab initio calculations and find good agreement between ab initio O-O distance and those obtained from classical molecular dynamics simulations. The reversibility of the mentioned transitions is confirmed by decompressing the systems.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000393943300005 Publication Date 2017-02-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9950;2469-9969; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 23 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:141994 Serial 4558  
Permanent link to this record
 

 
Author Bourgeois, J.; Hervieu, M.; Poienar, M.; Abakumov, A.M.; Elkaïm, E.; Sougrati, M.T.; Porcher, F.; Damay, F.; Rouquette, J.; Van Tendeloo, G.; Maignan, A.; Haines, J.; Martin, C.; url  doi
openurl 
  Title Evidence of oxygen-dependent modulation in LuFe2O4 Type A1 Journal article
  Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 85 Issue 6 Pages (down) 064102-064120,10  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract A polycrystalline sample of LuFe2O4 has been investigated by means of powder synchrotron x-ray and neutron diffraction and transmission electron microscopy (TEM), along with Mössbauer spectroscopy and transport and magnetic properties. A monoclinic distortion is unambiguously evidenced, and the crystal structure is refined in the monoclinic C2/m space group [aM = 5.9563(1) Å, bM = 3.4372(1) Å, cM = 8.6431(1) Å, β = 103.24(1)°]. Along with the previously reported modulations distinctive of the charge-ordering (CO) of the iron species, a new type of incommensurate order is observed, characterized by a vector q⃗1 = α1a⃗M* + γ1c⃗M* (with α1 ≅ 0.55, γ1 ≅ 0.13). In situ heating TEM observations from 300 to 773 K confirm that the satellites associated with q⃗1 vanish completely, only at a temperature significantly higher than the CO temperature. This incommensurate modulation has a displacive character and corresponds primarily to a transverse displacive modulation wave of the Lu cations position, as revealed by the high resolution, high angle annular dark field scanning TEM images and in agreement with synchrotron data refinements. Analyses of vacuum-annealed samples converge toward the hypothesis of a new ordering mechanism, associated with a tiny oxygen deviation from the O4 stoichiometry.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000299896900003 Publication Date 2012-02-06  
  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 24 Open Access  
  Notes Hercules Approved Most recent IF: 3.836; 2012 IF: 3.767  
  Call Number UA @ lucian @ c:irua:95042 Serial 1095  
Permanent link to this record
 

 
Author Neek-Amal, M.; Xu, P.; Qi, D.; Thibado, P.M.; Nyakiti, L.O.; Wheeler, V.D.; Myers-Ward, R.L.; Eddy, C.R.; Gaskill, D.K.; Peeters, F.M. url  doi
openurl 
  Title Membrane amplitude and triaxial stress in twisted bilayer graphene deciphered using first-principles directed elasticity theory and scanning tunneling microscopy Type A1 Journal article
  Year 2014 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 90 Issue 6 Pages (down) 064101  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Twisted graphene layers produce a moire pattern (MP) structure with a predetermined wavelength for a given twist angle. However, predicting the membrane corrugation amplitude for any angle other than pure AB-stacked or AA-stacked graphene is impossible using first-principles density functional theory (DFT) due to the large supercell. Here, within elasticity theory, we define the MP structure as the minimum-energy configuration, thereby leaving the height amplitude as the only unknown parameter. The latter is determined from DFT calculations for AB-and AA-stacked bilayer graphene in order to eliminate all fitting parameters. Excellent agreement with scanning tunneling microscopy results across multiple substrates is reported as a function of twist angle.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000339995800001 Publication Date 2014-08-01  
  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 12 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. M.N.-A. was supported by the EU-Marie Curie IIF postdoctoral Fellowship No. 299855. P.M.T. is thankful for the financial support of the Office of Naval Research under Grant No. N00014-10-1-0181 and the National Science Foundation under Grant No. DMR-0855358. L.O.N. acknowledges the support of the American Society for Engineering Education and Naval Research Laboratory Postdoctoral Fellow Program. Work at the US Naval Research Laboratory is supported by the Office of Naval Research. ; Approved Most recent IF: 3.836; 2014 IF: 3.736  
  Call Number UA @ lucian @ c:irua:118774 Serial 1991  
Permanent link to this record
 

 
Author Torsello, D.; Ummarino, G.A.; Bekaert, J.; Gozzelino, L.; Gerbaldo, R.; Tanatar, M.A.; Canfield, P.C.; Prozorov, R.; Ghigo, G. url  doi
openurl 
  Title Tuning the intrinsic anisotropy with disorder in the CaKFE₄As₄ superconductor Type A1 Journal article
  Year 2020 Publication Physical Review Applied Abbreviated Journal Phys Rev Appl  
  Volume 13 Issue 6 Pages (down) 064046-64049  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We report on the anisotropy of the London penetration depth of CaKFe4As4, discussing how it relates to its electronic structure and how it modifies under introduction of disorder, both chemically induced (by Ni substitution) and irradiation induced (by 3.5-MeV protons). Indeed, CaKFe4As4 is particularly suitable for the study of fundamental superconducting properties due to its stoichiometric composition, exhibiting clean-limit behavior in the pristine samples and having a fairly high critical temperature, T-c approximate to 35 K. The London penetration depth lambda(L) is measured with a microwave-coplanar-resonator technique that allows us to deconvolve the anisotropic contributions lambda(L,ab) and lambda(L,c) and obtain the anisotropy parameter gamma(lambda) = lambda(L,c)/lambda(L,ab). The gamma(lambda) (T) found for the undoped pristine sample is in good agreement with previous literature and is here compared to ab initio density-functional-theory and Eliashberg calculations. The dependence of gamma(lambda) (T) on both chemical and irradiation-induced disorder is discussed to highlight which method is more suitable to decrease the direction dependence of the electromagnetic properties while maintaining a high critical temperature. Lastly, the relevance of an intrinsic anisotropy such as gamma(lambda) on application-related anisotropic parameters (critical current, pinning) is discussed in light of the recent employment of CaKFe4As4 in the production of wires.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000540915800003 Publication Date 2020-06-19  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2331-7019 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.6 Times cited 4 Open Access  
  Notes ; This work was partially supported by the Italian Ministry of Education, University and Research (Project PRIN “HIBiSCUS,” Grant No. 201785KWLE). J.B. acknowledges the support of a postdoctoral fellowship of the Research Foundation-Flanders (FWO). The computational resources and services used for the first-principles calculations in this work were provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government-department EWI. Work done at Ames Laboratory was supported by the U.S. Department of Energy, Office of Basic Energy Science, Division of Materials Sciences and Engineering. Ames Laboratory is operated for the U.S. Department of Energy by Iowa State University under Contract No. DE-AC02-07CH11358. G.A.U. acknowledges support from the MEPhI Academic Excellence Project (Contract No. 702.a03.21.0005). ; Approved Most recent IF: 4.6; 2020 IF: 4.808  
  Call Number UA @ admin @ c:irua:170178 Serial 6641  
Permanent link to this record
 

 
Author Sethu, K.K.V.; Ghosh, S.; Couet, S.; Swerts, J.; Sorée, B.; De Boeck, J.; Kar, G.S.; Garello, K. doi  openurl
  Title Optimization of tungsten beta-phase window for spin-orbit-torque magnetic random-access memory Type A1 Journal article
  Year 2021 Publication Physical Review Applied Abbreviated Journal Phys Rev Appl  
  Volume 16 Issue 6 Pages (down) 064009  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Switching induced by spin-orbit torque (SOT) is being vigorously explored, as it allows the control of magnetization using an in-plane current, which enables a three-terminal magnetic-tunnel-junction geometry with isolated read and write paths. This significantly improves the device endurance and the read stability, and allows reliable subnanosecond switching. Tungsten in the beta phase, beta-W, has the largest reported antidamping SOT charge-to-spin conversion ratio (theta(AD) approximate to -60%) for heavy metals. However, beta-W has a limitation when one is aiming for reliable technology integration: the beta phase is limited to a thickness of a few nanometers and enters the alpha phase above 4 nm in our samples when industry-relevant deposition tools are used. Here, we report our approach to extending the range of beta-W, while simultaneously improving the SOT efficiency by introducing N and O doping of W. Resistivity and XRD measurements confirm the extension of the beta phase from 4 nm to more than 10 nm, and transport characterization shows an effective SOT efficiency larger than -44.4% (reaching approximately -60% for the bulk contribution). In addition, we demonstrate the possibility of controlling and enhancing the perpendicular magnetic anisotropy of a storage layer (Co-Fe-B). Further, we integrate the optimized W(O, N) into SOT magnetic random-access memory (SOT-MRAM) devices and project that, for the same thickness of SOT material, the switching current decreases by 25% in optimized W(O, N) compared with our standard W. Our results open the path to using and further optimizing W for integration of SOT-MRAM technology.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000729005800002 Publication Date 2021-12-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2331-7019 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.808 Times cited Open Access Not_Open_Access  
  Notes Approved Most recent IF: 4.808  
  Call Number UA @ admin @ c:irua:184832 Serial 7007  
Permanent link to this record
 

 
Author Vanraes, P.; Parayil Venugopalan, S.; Besemer, M.; Bogaerts, A. pdf  url
doi  openurl
  Title Assessing neutral transport mechanisms in aspect ratio dependent etching by means of experiments and multiscale plasma modeling Type A1 Journal Article
  Year 2023 Publication Plasma Sources Science and Technology Abbreviated Journal Plasma Sources Sci. Technol.  
  Volume 32 Issue 6 Pages (down) 064004  
  Keywords A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;  
  Abstract Since the onset of pattern transfer technologies for chip manufacturing, various strategies have been developed to circumvent or overcome aspect ratio dependent etching (ARDE). These methods have, however, their own limitations in terms of etch non-idealities, throughput or costs. Moreover, they have mainly been optimized for individual in-device features and die-scale patterns, while occasionally ending up with poor patterning of metrology marks, affecting the alignment and overlay in lithography. Obtaining a better understanding of the underlying mechanisms of ARDE and how to mitigate them therefore remains a relevant challenge to date, for both marks and advanced nodes. In this work, we accordingly assessed the neutral transport mechanisms in ARDE by means of experiments and multiscale modeling for SiO<sub>2</sub>etching with CHF<sub>3</sub>/Ar and CF<sub>4</sub>/Ar plasmas. The experiments revealed a local maximum in the etch rate for an aspect ratio around unity, i.e. the simultaneous occurrence of regular and inverse reactive ion etching lag for a given etch condition. We were able to reproduce this ARDE trend in the simulations without taking into account charging effects and the polymer layer thickness, suggesting shadowing and diffuse reflection of neutrals as the primary underlying mechanisms. Subsequently, we explored four methods with the simulations to regulate ARDE, by varying the incident plasma species fluxes, the amount of polymer deposition, the ion energy and angular distribution and the initial hardmask sidewall angle, for which the latter was found to be promising in particular. Although our study focusses on feature dimensions characteristic to metrology marks and back-end-of-the-line integration, the obtained insights have a broader relevance, e.g. to the patterning of advanced nodes. Additionally, this work supports the insight that physisorption may be more important in plasma etching at room temperature than originally thought, in line with other recent studies, a topic on which we recommend further research.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 001021250100001 Publication Date 2023-06-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0963-0252 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.8 Times cited Open Access Not_Open_Access  
  Notes P Vanraes acknowledges funding by ASML for the project ‘Computational simulation of plasma etching of trench structures’. P Vanraes and A Bogaerts want to express their gratitude to Mark J Kushner (University of Michigan) for the sharing of the HPEM and MCFPM codes, and for the interesting exchange of views. P Vanraes wishes to thank Violeta Georgieva and Stefan Tinck for the fruitful discussions on the HPEM code, Yu-Ru Zhang for an example of the CCP reactor code and Karel Venken for his technical help with the server maintenance and use. S P Venugopalan and M Besemer wish to thank Luigi Scaccabarozzi, Sander Wuister, Coen Verschuren, Michael Kubis, Kuan-Ming Chen, Ruben Maas, Huaichen Zhang and Julien Mailfert (ASML) for the insightful discussions. Approved Most recent IF: 3.8; 2023 IF: 3.302  
  Call Number PLASMANT @ plasmant @c:irua:197760 Serial 8811  
Permanent link to this record
 

 
Author Clark, L.; Guzzinati, G.; Béché, A.; Lubk, A.; Verbeeck, J. pdf  url
doi  openurl
  Title Symmetry-constrained electron vortex propagation Type A1 Journal article
  Year 2016 Publication Physical review A Abbreviated Journal Phys Rev A  
  Volume 93 Issue 93 Pages (down) 063840  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Electron vortex beams hold great promise for development in transmission electron microscopy but have yet to be widely adopted. This is partly due to the complex set of interactions that occur between a beam carrying orbital angular momentum (OAM) and a sample. Herein, the system is simplified to focus on the interaction between geometrical symmetries, OAM, and topology. We present multiple simulations alongside experimental data to study the behavior of a variety of electron vortex beams after interacting with apertures of different symmetries and investigate the effect on their OAM and vortex structure, both in the far field and under free-space propagation.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000378197200006 Publication Date 2016-06-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9926 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.925 Times cited 7 Open Access  
  Notes L.C., A.B., G.G., and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510—VORTEX. J.V. and A.L. acknowledge financial support from the European Union through the 7th Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2). The Qu-Ant-EM microscope was partly funded by the Hercules fund of the Flemish Government.; esteem2jra3; ECASJO; Approved Most recent IF: 2.925  
  Call Number c:irua:134086 c:irua:134086 Serial 4090  
Permanent link to this record
 

 
Author Papp, G.; Peeters, F.M. doi  openurl
  Title Magnetoresistance in a hybrid ferromagnetic/semiconductor device Type A1 Journal article
  Year 2010 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 107 Issue 6 Pages (down) 063718,1-063718,4  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Ballistic transport of a two-dimensional electron gas (2DEG) in a rectangle shaped wire, subjected to a local nonhomogeneous magnetic field that results from an in-plane magnetized ferromagnetic (FM) strip deposited above the 2DEG, is investigated theoretically. We found a positive magnetoresistance (MR), which exhibits hysteresis behavior with respect to the direction of the magnetic field sweep, in agreement with a recent experiment. This positive MR can be tuned by applying a gate voltage to the FM strip.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000276210800063 Publication Date 2010-04-01  
  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 10 Open Access  
  Notes ; ; Approved Most recent IF: 2.068; 2010 IF: 2.079  
  Call Number UA @ lucian @ c:irua:82281 Serial 1927  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: