“Self-consistent g* factor and spin-split Landau levels in strong magnetic fields and at low temperatures”. Xu W, Vasilopoulos P, Das MP, Peeters FM, , 743 (1995)
Keywords: P3 Proceeding; Condensed Matter Theory (CMT)
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“Collective excitations in three-dimensional Dirac systems”. Li QN, Vasilopoulos P, Peeters FM, Xu W, Xiao YM, Milošević, MV, Physical review B 109, 115123 (2024). http://doi.org/10.1103/PHYSREVB.109.115123
Abstract: We provide the plasmon spectrum and related properties of the three-dimensional (3D) Dirac semimetals Na 3 Bi and Cd 3 As 2 based on the random -phase approximation. The necessary one -electron eigenvalues and eigenfunctions are obtained from an effective k <middle dot> p Hamiltonian. Below the energy at which the velocity v z along the k z axis vanishes, the density of states differs drastically from that of a 3D electron gas (3DEG) or graphene. The dispersion relation is anisotropic for wave vectors parallel ( q ) and perpendicular ( q z ) to the ( x , y ) plane and is markedly different than that of graphene or a 3DEG. The same holds for the energy -loss function. Both depend sensitively on the position of the Fermi energy E F relative to the region of the Berry curvature of the bands. For E F below the energy at which v z vanishes, the range of the relevant wave vectors q and q z shrinks, for q z by about one order of magnitude.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.7
DOI: 10.1103/PHYSREVB.109.115123
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“Angular confinement and direction-dependent transmission in graphene nanostructures with magnetic barriers”. Masir MR, Vasilopoulos P, Matulis A, Peeters FM, AIP conference proceedings 1199, 363 (2009). http://doi.org/10.1063/1.3295453
Abstract: We evaluate the transmission through magnetic barriers in graphene-based nanostructures. Several particular cases are considered: a magnetic step, single and double barriers, delta -function barriers as well as barrier structures with inhomogeneous magnetic field profiles but with average magnetic field equal to zero. The transmission exhibits a strong dependence on the direction of the incident wave vector. In general the resonant structure of the transmission is significantly more pronounced for (Dirac) electrons with linear spectrum compared to that for electrons with a parabolic one.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
DOI: 10.1063/1.3295453
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“Band structure, density of states, and transmission in graphene bilayer superlattices”. Barbier M, Vasilopoulos P, Peeters FM, Pereira JM, AIP conference proceedings 1199, 547 (2009). http://doi.org/10.1063/1.3295550
Abstract: The energy spectrum and density of states of graphene bilayer superlattices (SLs) are evaluated. We take into account doping and/or gating of the layers as well as tunnel coupling between them. In addition, we evaluate the transmission through such SLs and through single or double barriers. The transmission exhibits a strong dependence on the direction of the incident wave vector.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
DOI: 10.1063/1.3295550
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“Graphene-based quantum wires”. Pereira JM Jr, Mlinar V, Peeters FM, Vasilopoulos P, AIP conference proceedings
T2 –, 28th International Conference on the Physics of Semiconductors (ICPS-28), JUL 24-28, 2006, Vienna, AUSTRIA , 721 (2007)
Abstract: We investigate the properties of carriers in graphene-based quantum wires created by potential barriers, by means of analytical and numerical calculations. We obtain expressions for the energy spectrum as a function of barrier height, well width and linear momentum along the wire. The results demonstrate a direction-dependent resonant transmission across the potential well.
Keywords: P1 Proceeding; Condensed Matter Theory (CMT)
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“Influence of spin-orbit interaction on the magnetotransport of a periodically modulated two-dimensional electron gas”. Wang XF, Vasilopoulos P, Peeters FM, International journal of modern physics: B: condensed matter physics, statistical physics, applied physics
T2 –, 16th International Conference on High Magnetic Fields in Semiconductor, Physics, AUG 02-06, 2004, Florida State Univ, NHMFL, Tallahassee, FL 18, 3653 (2004). http://doi.org/10.1142/S0217979204027220
Abstract: Transport properties of a two-dimensional electron gas (2DEG) are studied in the presence of a normal magnetic field B, of a weak one-dimensional (1D) periodic potential modulation V(x) = V(0)cos(Kx), and of the Rashba spin-orbit interaction (SOI) of strength a. For V(x) = 0 the SOI mixes the up and down spin states of neighboring Landau levels into two, unequally spaced energy branches. For V(x) not equal 0 these levels broaden into bands and their bandwidths oscillate with B. The n-th level bandwidth of each series vanishes at different values of B. Relative to the ID-modulated 2DEG without SOI and one flat-band condition, there are two flat-band conditions that depend on a and the transport coefficients can change considerably. For weak a the Weiss oscillations show beating patterns while for strong a the Shubnikov-de Haas ones axe split in two.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 0.736
DOI: 10.1142/S0217979204027220
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“Landau-level dispersion and the quantum Hall plateaus in bilayer graphene”. Zarenia M, Vasilopoulos P, Pourtolami N, Peeters FM, AIP conference proceedings 1566, 275 (2013). http://doi.org/10.1063/1.4848392
Abstract: We study the quantum Hall effect (QHE) in bilayer graphene using the Kubo-Greenwood formula. At zero temperature the Hall conductivity sigma(yx) is given by sigma(yx) – 4(N + 1)e(2)/h with N the index of the highest occupied Landau level (LL). Including the dispersion of the LLs and their width, due to e. g. scattering by impurities, produces the plateau of the n = 0 LL in agreement with experimental results on doped samples and similar theoretical results on single-layer graphene plateaus widen with impurity concentration. Further, the evaluated resistivity rho(xx) exhibits a strong, oscillatory dependence on the electron concentration. Explicit results are obtained for delta-function impurities.
Keywords: P1 Proceeding; Condensed Matter Theory (CMT)
DOI: 10.1063/1.4848392
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“Magneto resistance oscillations in a modulated 2DEG periodic in the ratio h/e to flux per unit cell”. Vasilopoulos P, Wang XF, Peeters FM, Chowdhury S, Long AR, Davies JH, Physica. E: Low-dimensional systems and nanostructures
T2 –, 15th International Conference on Electronic Properties of, Two-Dimensional Systems (EP2DS-15), JUL 14-18, 2003, Nara, JAPAN 22, 389 (2004). http://doi.org/10.1016/j.physe.2003.12.028
Abstract: Transport properties of the 2DEG are studied in the presence of a normal magnetic field B and of a weak, two-dimensional periodic potential modulation. A tight-binding treatment has shown that each Landau level splits into several subbands with exponentially small gaps between them. Assuming the latter are closed due to disorder gives analytical wave functions and simplifies the evaluation of the magnetoresistance tensor p(muv) The relative phase of the oscillations in p(xx) and p(yy) depends on the modulation strengths and periods. For short periods less than or equal to 100 nm, in addition to the Weiss oscillations, the collisional contribution to the conductivity and the corresponding resistivity contribution show prominent peaks when one flux quantum h/e passes through an integral number of unit cells in good agreement with experiments. For periods 300-400 nm long used in early experiments, these peaks occur at fields 10-25 times smaller than those of the Weiss oscillations and are not resolved. (C) 2003 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 2.221
DOI: 10.1016/j.physe.2003.12.028
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“Square-wave conductance through a chain of rings due to spin-orbit interaction”. Molnar B, Vasilopoulos P, Peeters FM, AIP conference proceedings 772, 1335 (2005)
Abstract: We study ballistic electron transport through a finite chain of quantum circular rings in the presence of spin-orbit interaction (SOI) of strength alpha. The transmission and reflection coefficients for a single ring, obtained analytical lylead to the conductance for a chain of rings as a function of alpha and of the wave vector k of the incident electron. Due to destructive spin interferences the chain can be totaly opaque for certain ranges of k the width of which depends on the value of alpha. A periodic modulation of a widens up the gaps considerably and produces a nearly binary conductance output.
Keywords: P1 Proceeding; Condensed Matter Theory (CMT)
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“Magnetoconductance through a chain of rings in the presence of spin-orbit interaction”. Vasilopoulos P, Molnar B, Peeters FM, International journal of modern physics: B: condensed matter physics, statistical physics, applied physics 18, 3661 (2004). http://doi.org/10.1142/S0217979204027244
Abstract: Ballistic electron transport through a finite chain of quantum circular rings is studied in the presence of the Rashba coupling, of strength a, and of a perpendicular magnetic field B. The transmission and reflection coefficients for a single ring, obtained analytically, help obtain the conductance through a chain of rings as a function of the strength a, the field B, and of the wave vector k of the incident electron. Due to destructive spin interferences caused by the Rashba coupling the chain can be totally opaque for certain ranges of k the width of which depends on values of a and B. Outside these ranges the conductance oscillates with high values between e(2)/h and 2e(2)/h. The effect of a periodic modulation of a or B on the conductance gaps is investigated. A periodic, square-wave conductance pattern, pertinent to the development of the spin transistor, results within wide stripes in the parameter space spanned by k, a, and B. Finite temperatures smoothen the square-wave profile of the conductance but do not alter its periodic character.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 0.736
Times cited: 2
DOI: 10.1142/S0217979204027244
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“Two-dimensional tunneling through magnetic barriers”. Matulis A, Peeters FM, Vasilopoulos P, Surface science : a journal devoted to the physics and chemistry of interfaces 305, 434 (1994). http://doi.org/10.1016/0039-6028(94)90931-8
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.925
Times cited: 2
DOI: 10.1016/0039-6028(94)90931-8
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“Electric-field manipulation of spin states in confined non-magnetic/magnetic heterostructures”. Borza S, Peeters FM, Vasilopoulos P, Papp G, Journal of physics : condensed matter 19, 176221 (2007). http://doi.org/10.1088/0953-8984/19/17/176221
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.649
Times cited: 4
DOI: 10.1088/0953-8984/19/17/176221
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“Coupled electron-hole transport: generalized random-phase approximation and density functional theory”. Tso HC, Vasilopoulos P, Peeters FM, Surface science : a journal devoted to the physics and chemistry of interfaces 305, 400 (1994). http://doi.org/10.1016/0039-6028(94)90925-3
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.925
Times cited: 5
DOI: 10.1016/0039-6028(94)90925-3
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“Band structure of a two-dimensional electron gas in the presence of two-dimensional electric and magnetic modulations and a perpendicular magnetic field”. Wang XF, Vasilopoulos P, Peeters FM, Physical review : B : condensed matter and materials physics 70, 155312 (2004). http://doi.org/10.1103/PhysRevB.70.155312
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 6
DOI: 10.1103/PhysRevB.70.155312
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“Snake orbits in hybrid semiconductor/ferromagnetic devices”. Peeters FM, Reijniers J, Badalian SM, Vasilopoulos P, Microelectronic engineering 47, 405 (1999). http://doi.org/10.1016/S0167-9317(99)00245-2
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Engineering Management (ENM)
Impact Factor: 1.806
Times cited: 6
DOI: 10.1016/S0167-9317(99)00245-2
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“Landau levels in biased graphene structures with monolayer-bilayer interfaces”. Mirzakhani M, Zarenia M, Vasilopoulos P, Ketabi SA, Peeters FM, Physical review B 96, 125430 (2017). http://doi.org/10.1103/PHYSREVB.96.125430
Abstract: The electron energy spectrum in monolayer-bilayer-monolayer and in bilayer-monolayer-bilayer graphene structures is investigated and the effects of a perpendicular magnetic field and electric bias are studied. Different types of monolayer-bilayer interfaces are considered as zigzag (ZZ) or armchair (AC) junctions which modify considerably the bulk Landau levels (LLs) when the spectra are plotted as a function of the center coordinate of the cyclotron orbit. Far away from the two interfaces, one obtains the well-known LLs for extended monolayer or bilayer graphene. The LL structure changes significantly at the two interfaces or junctions where the valley degeneracy is lifted for both types of junctions, especially when the distance between them is approximately equal to the magnetic length. Varying the nonuniform bias and the width of this junction-to-junction region in either structure strongly influence the resulting spectra. Significant differences exist between ZZ and AC junctions in both structures. The densities of states (DOSs) for unbiased structures are symmetric in energy whereas those for biased structures are asymmetric. An external bias creates interface LLs in the gaps between the LLs of the unbiased system in which the DOS can be quite small. Such a pattern of LLs can be probed by scanning tunneling microscopy.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 6
DOI: 10.1103/PHYSREVB.96.125430
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“Electrostatically confined trilayer graphene quantum dots”. Mirzakhani M, Zarenia M, Vasilopoulos P, Peeters FM, Physical review B 95, 155434 (2017). http://doi.org/10.1103/PHYSREVB.95.155434
Abstract: Electrically gating of trilayer graphene (TLG) opens a band gap offering the possibility to electrically engineer TLG quantum dots. We study the energy levels of such quantum dots and investigate their dependence on a perpendicular magnetic field B and different types of stacking of the graphene layers. The dots are modeled as circular and confined by a truncated parabolic potential which can be realized by nanostructured gates or position-dependent doping. The energy spectra exhibit the intervalley symmetry E-K(e) (m) = -E (h)(K') (m) for the electron (e) and hole (h) states, where m is the angular momentum quantum number and K and K' label the two valleys. The electron and hole spectra for B = 0 are twofold degenerate due to the intervalley symmetry E-K (m) = E-K' [-(m + 1)]. For both ABC [alpha = 1.5 (1.2) for large (small) R] and ABA (alpha = 1) stackings, the lowest-energy levels show approximately a R-alpha dependence on the dot radius R in contrast with the 1/R-3 one for ABC-stacked dots with infinite-mass boundary. As functions of the field B, the oscillator strengths for dipole-allowed transitions differ drastically for the two types of stackings.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Times cited: 6
DOI: 10.1103/PHYSREVB.95.155434
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“Photo-excited carriers and optical conductance and transmission in graphene in the presence of phonon scattering”. Dong HM, Xu W, Zhang J, Peeters FM, Vasilopoulos P, Physica. E: Low-dimensional systems and nanostructures 42, 748 (2010). http://doi.org/10.1016/j.physe.2009.11.048
Abstract: We present a theoretical study of the optoelectronic properties of monolayer graphene. Including the effect of the electron-photon-phonon scattering, we employ the mass- and energy-balance equations derived from the Boltzmann equation to evaluate self-consistently the carrier densities, optical conductance and transmission coefficient in graphene in the presence of linearly polarized radiation field. We find that the photo-excited carrier density can be increased under infrared radiation and depend strongly on radiation intensity and frequency. For short wavelengths (lambda <3 mu m), the universal optical conductance sigma(0) = e(2)/4h is obtained and the light transmittance is about 0.97-0.98. Interestingly, there is an optical absorption window in the range 4-100 mu m which is induced by different transition energies required for inter- and intra-band optical absorption. The position and width of this absorption window depend sensitively on temperature and carrier density of the system. These results are relevant for applications of recently developed graphene devices in advanced optoelectronics such as the infrared photodetectors. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 2.221
Times cited: 7
DOI: 10.1016/j.physe.2009.11.048
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“Density of states and Fermi level of a periodically modulated two-dimensional electron gas”. Peeters FM, Vasilopoulos P, Shi J, Journal of physics : condensed matter 14, 8803 (2002). http://doi.org/10.1088/0953-8984/14/38/305
Abstract: Explicit analytic expressions are obtained for the density of states D(E) and Fermi energy E-F of a two-dimensional electron gas in the presence of a weak and periodic unidirectional electric or magnetic modulation and of a uniform perpendicular magnetic field B. The Landau levels broaden into bands and their width, proportional to the modulation strength, oscillates with B and gives rise to Weiss oscillations in D(E), E-F and the transport coefficients. When both electric and magnetic modulations are present the position of the resulting oscillations depends on the ratio delta between the two modulation strengths. When the modulations are out of phase there is no shift in the position of the oscillations when delta varies and for a particular value of delta the oscillations are suppressed.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.649
Times cited: 8
DOI: 10.1088/0953-8984/14/38/305
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“Quantum magnetotransport of a 2-dimensional electron-gas subject to periodic electric or magnetic modulations”. Vasilopoulos, Peeters FM, Physica scripta : supplements
T2 –, 11TH GENERAL CONF OF THE CONDENSED MATTER DIVISION OF THE EUROPEAN, PHYSICAL SOC, APR 08-11, 1991, EXETER, ENGLAND T39, 177 (1991). http://doi.org/10.1088/0031-8949/1991/T39/027
Abstract: Electrical transport properties of the two-dimensional electron gas are studied in the presence of a perpendicular magnetic field B = Bz and of a weak one-dimensional electric (V0 cos (Kx)) or magnetic (B0 = B0 cos (Kx)z) modulation where B0 << B, K = 2-pi/a, and a is the modulation period. In either case the discrete Landau levels broaden into bands whose width: (1) is proportional to the modulation strength, (2) it oscillates with B, and (3) it gives rise to magnetoresistance oscillations, at low B, that are different in period and temperature dependence from the Shubnikov-de Haas (SdH) ones, at higher B. For equal energy modulation strengths, V0 = heB0/m*, the magnetic bandwidth at the Fermi energy is about one order of magnitude larger than the electric one. The same holds for the oscillation amplitude of the electrical magnetoresistivity tensor. For two-dimensional modulations the energy spectrum has the same structure but with different scales. For weak magnetic fields and equal modulation strengths the gaps in the spectrum can be much larger in the magnetic case thus making easier the observability of the spectrum's fine structure.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.126
Times cited: 8
DOI: 10.1088/0031-8949/1991/T39/027
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“Quantum magnetotransport of a two-dimensional electron gas subject to periodic electric and magnetic modulations”. Vasilopoulos P, Peeters FM, Physica scripta T39, 177 (1991)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.126
Times cited: 8
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“Resonant tunneling in graphene microstructures”. Milton Pereira J, Vasilopoulos P, Peeters FM, Microelectronics journal 39, 534 (2008). http://doi.org/10.1016/j.mejo.2007.07.099
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.163
Times cited: 9
DOI: 10.1016/j.mejo.2007.07.099
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“Inverse flux quantum periodicity of magnetoresistance oscillations in two-dimensional short-period surface superlattices”. Wang XF, Vasilopoulos P, Peeters FM, Physical review : B : condensed matter and materials physics 69, 035331 (2004). http://doi.org/10.1103/PhysRevB.69.035331
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 10
DOI: 10.1103/PhysRevB.69.035331
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“Graphene quantum dot with a Coulomb impurity : subcritical and supercritical regime”. Van Pottelberge R, Zarenia M, Vasilopoulos P, Peeters FM, Physical review B 95, 245410 (2017). http://doi.org/10.1103/PHYSREVB.95.245410
Abstract: We study the influence of confinement on the atomic collapse due to a Coulomb impurity placed at the center of a graphene quantum dot of radius R. We apply the zigzag or infinite-mass boundary condition and consider both a point-size and a finite-size impurity. As a function of the impurity strength Za, the energy spectra are discrete. In the case of the zigzag boundary condition, the degenerate (with respect to the angular momentum m) zero-energy levels are pulled down in energy as Z alpha increases, and they remain below epsilon = – Z alpha. Our results show that the energy levels exhibit a 1/R dependence in the subcritical regime [Z alpha < |km + 1/2|, k = 1 (-1) for the K (K') valley]. In the supercritical regime (Z alpha > |km + 1/2|) we find a qualitatively very different behavior where the levels decrease as a function of R in a nonmonotonic manner. While the valley symmetry is preserved in the presence of the impurity, we find that the impurity breaks electron-hole symmetry. We further study the energy spectrum of zigzag quantum dots in gapped graphene. Our results show that as the gap increases, the lowest electron states are pushed into the gap by the impurity.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 13
DOI: 10.1103/PHYSREVB.95.245410
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“Spin- and valley-dependent commensurability oscillations and electric-field-induced quantum Hall plateaux in periodically modulated silicene”. Shakouri K, Vasilopoulos P, Vargiamidis V, Hai G-Q, Peeters FM, Applied physics letters 104, 213109 (2014). http://doi.org/10.1063/1.4878509
Abstract: We study the commensurability oscillations in silicene subject to a perpendicular electric field E-z, a weak magnetic field B, and a weak periodic potential V = V-0 cos(Cy); C = 2 pi/a(0) with a(0) its period. The field E-z and/or the modulation lift the spin degeneracy of the Landau levels and lead to spin and valley resolved Weiss oscillations. The spin resolution is maximal when the field E-z is replaced by a periodic one E-z = E-0 cos(Dy); D = 2 pi/b(0), while the valley one is maximal for b(0) = a(0). In certain ranges of B values, the current is fully spin or valley polarized. Additional quantum Hall conductivity plateaux arise due to spin and valley intra-Landau-level transitions. (C) 2014 AIP Publishing LLC.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
Times cited: 16
DOI: 10.1063/1.4878509
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“Aharonov-Bohm oscillations in phosphorene quantum rings”. Li LL, Moldovan D, Vasilopoulos P, Peeters FM, Physical review B 95, 205426 (2017). http://doi.org/10.1103/PHYSREVB.95.205426
Abstract: The Aharonov-Bohm (AB) effect in square phosphorene quantum rings, with armchair and zigzag edges, is investigated using the tight-binding method. The energy spectra and wave functions of such rings, obtained as a function of the magnetic flux Phi threading the ring, are strongly influenced by the ringwidthW, an in-plane electric field E-p, and a side-gating potential V-g. Compared to a square dot, the ring shows an enhanced confinement due to its inner edges and an interedge coupling along the zigzag direction, both of which strongly affect the energy spectrum and the wave functions. The energy spectrum that is gapped consists of a regular part, of conduction (valence) band states, that shows the usual AB oscillations in the higher-(lower-) energy region, and of edge states, in the gap, that exhibit no AB oscillations. As the width W decreases, the AB oscillations become more distinct and regular and their period is close to Phi(0)/2, where the flux quantum Phi(0) = h/e is the period of an ideal circular ring (W -> 0). Both the electric field E-p and the side-gating potential V-g reduce the amplitude of the AB oscillations. The amplitude can be effectively tuned by E-p or V-g and exhibits an anisotropic behavior for different field directions or side-gating configurations.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 16
DOI: 10.1103/PHYSREVB.95.205426
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“The low-temperature self-consistent g factor for heterostructures in strong magnetic fields”. Xu W, Vasilopoulos P, Das MP, Peeters FM, Journal of physics : condensed matter 7, 4419 (1995)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.346
Times cited: 20
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“Magnetotransport in periodically modulated bilayer graphene”. Zarenia M, Vasilopoulos P, Peeters FM, Physical review : B : condensed matter and materials physics 85, 245426 (2012). http://doi.org/10.1103/PhysRevB.85.245426
Abstract: Magnetotransport in bilayer graphene in the presence of a weak and periodic potential is investigated in the presence of a perpendicular magnetic field B. The modulation broadens the Landau levels into bands and for weak magnetic fields leads to the well-known Weiss oscillations in their bandwidth and their transport coefficients at very low B and to the Shubnikov-de Haas oscillations at larger B. The amplitude of the Weiss oscillations is severely reduced if the periodic potentials applied to the two layers oscillate out of phase. We also contrast some results with those corresponding to single-layer graphene. Relative to them the flat-band condition and the oscillation amplitude differ substantially, due to the interlayer coupling, and agree only when this coupling is extremely weak. We further show that the Hall conductivity exhibits the well-known steps at half-integer and integer multiples of 4e(2)/h in single-layer and bilayer graphene, respectively, even for very weak magnetic fields. The results are pertinent to weak and periodic corrugations when the potential modulation dominates the strain-induced magnetic modulation.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 21
DOI: 10.1103/PhysRevB.85.245426
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“Confined magnetic guiding orbit states”. Reijniers J, Matulis A, Chang K, Peeters FM, Vasilopoulos P, Europhysics letters 59, 749 (2002). http://doi.org/10.1209/epl/i2002-00189-8
Abstract: We show how snake-orbit states which run along a magnetic edge can be confined electrically. We consider a two-dimensional electron gas (2DEG) confined into a quantum wire, subjected to a strong perpendicular and steplike magnetic field B/ − B. Close to this magnetic step, new, spatially confined bound states arise as a result of the lateral confinement and the magnetic-field step. The number of states, with energy below the first Landau level, increases as B becomes stronger or as the wire width becomes larger. These bound states can be understood as an interference between two counter-propagating one-dimensional snake-orbit states.
Keywords: A1 Journal article; Engineering Management (ENM); Condensed Matter Theory (CMT)
Impact Factor: 1.957
Times cited: 26
DOI: 10.1209/epl/i2002-00189-8
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“Spin-dependent transmission through a chain of rings : influence of a periodically modulated spin-orbit interaction strength or ring radius”. Molnar B, Vasilopoulos P, Peeters FM, Applied physics letters 85, 612 (2004). http://doi.org/10.1063/1.1775283
Abstract: We study ballistic electron transport through a finite chain of quantum circular rings in the presence of spin-orbit interaction of strength alpha. For a single ring, the transmission and reflection coefficients are obtained analytically and from them the conductance for a chain of rings as a function of alpha and of the wave vector k of the incident electron. We show that due to destructive spin interferences, the chain can be totally opaque for certain ranges of k, the width of which depends on the value of alpha. A periodic modulation of the strength alpha or of the ring radius widens the gaps considerably and produces a nearly binary conductance output. (C) 2004 American Institute of Physics.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
Times cited: 26
DOI: 10.1063/1.1775283
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