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“Mapping electronic reconstruction at the metal-insulator interface in LaVO3/SrVO3 heterostructures”. Tan H, Egoavil R, Béché, A, Martinez GT, Van Aert S, Verbeeck J, Van Tendeloo G, Rotella H, Boullay P, Pautrat A, Prellier W, Physical review : B : condensed matter and materials physics 88, 155123 (2013). http://doi.org/10.1103/PhysRevB.88.155123
Abstract: A (LaVO3)6/(SrVO3)(3) superlattice is studied with a combination of sub-A resolved scanning transmission electron microscopy and monochromated electron energy-loss spectroscopy. The V oxidation state is mapped with atomic spatial resolution enabling us to investigate electronic reconstruction at the LaVO3/SrVO3 interfaces. Surprisingly, asymmetric charge distribution is found at adjacent chemically symmetric interfaces. The local structure is proposed and simulated with a double channeling calculation which agrees qualitatively with our experiment. We demonstrate that local strain asymmetry is the likely cause of the electronic asymmetry of the interfaces. The electronic reconstruction at the interfaces extends much further than the chemical composition, varying from 0.5 to 1.2 nm. This distance corresponds to the length of charge transfer previously found in the (LaVO3)./(SrVO3). metal/insulating and the (LaAlO3)./(SrTiO3). insulating/insulating interfaces.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 15
DOI: 10.1103/PhysRevB.88.155123
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“Effect of Bi bilayers on the topological states of Bi2Se3 : a first-principles study”. Govaerts K, Park K, De Beule C, Partoens B, Lamoen D, Physical review : B : condensed matter and materials physics 90, 155124 (2014). http://doi.org/10.1103/PhysRevB.90.155124
Abstract: Bi2Se3 is a three-dimensional topological insulator which has been extensively studied because it has a single Dirac cone on the surface, inside a relatively large bulk band gap. However, the effect of two-dimensional topological insulator Bi bilayers on the properties of Bi2Se3 and vice versa, has not been explored much. Bi bilayers are often present between the quintuple layers of Bi2Se3, since (Bi2)n(Bi2Se3)m form stable ground-state structures. Moreover, Bi2Se3 is a good substrate for growing ultrathin Bi bilayers. By first-principles techniques, we first show that there is no preferable surface termination by either Bi or Se. Next, we investigate the electronic structure of Bi bilayers on top of, or inside a Bi2Se3 slab. If the Bi bilayers are on top, we observe a charge transfer to the quintuple layers that increases the binding energy of the surface Dirac cones. The extra states, originating from the Bi bilayers, were declared to form a topological Dirac cone, but here we show that these are ordinary Rashba-split states. This result, together with the appearance of a new Dirac cone that is localized slightly deeper, might necessitate the reinterpretation of several experimental results. When the Bi bilayers are located inside the Bi2Se3 slab, they tend to split the slab into two topological insulators with clear surface states. Interface states can also be observed, but an energy gap persists because of strong coupling between the neighboring quintuple layers and the Bi bilayers.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 30
DOI: 10.1103/PhysRevB.90.155124
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“First-principles study of transition metal impurities in Si”. Zhang Z, Partoens B, Chang K, Peeters FM, Physical review : B : condensed matter and materials physics 77, 155201 (2008). http://doi.org/10.1103/PhysRevB.77.155201
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 72
DOI: 10.1103/PhysRevB.77.155201
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“Stable single layer of Janus MoSO: strong out-of-plane piezoelectricity”. Yagmurcukardes M, Peeters FM, Physical Review B 101, 155205 (2020). http://doi.org/10.1103/PHYSREVB.101.155205
Abstract: Using density functional theory based first-principles calculations, we predict the dynamically stable 1H phase of a Janus single layer composed of S-Mo-O atomic layers. It is an indirect band gap semiconductor exhibiting strong polarization arising from the charge difference on the two surfaces. In contrast to 1H phases of MoS2 and MoO2, Janus MoSO is found to possess four Raman active phonon modes and a large out-of-plane piezoelectric coefficient which is absent in fully symmetric single layers of MoS2 and MoO2. We investigated the electronic and phononic properties under applied biaxial strain and found an electronic phase transition with tensile strain while the conduction band edge displays a shift when under compressive strain. Furthermore, single-layer MoSO exhibits phononic stability up to 5% of compressive and 11% of tensile strain with significant phonon shifts. The phonon instability is shown to arise from the soft in-plane and out-of-plane acoustic modes at finite wave vector. The large strain tolerance of Janus MoSO is important for nanoelastic applications. In view of the dynamical stability even under moderate strain, we expect that Janus MoSO can be fabricated in the common 1H phase with a strong out-of-plane piezoelectric coefficient.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.7
Times cited: 66
DOI: 10.1103/PHYSREVB.101.155205
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“Free-carrier effects in gallium nitride epilayers: Valence-band dispersion”. Shields PA, Nicholas RJ, Peeters FM, Beaumont B, Gibart P, Physical Review B 64, 155303 (2001). http://doi.org/10.1103/PhysRevB.64.081203
Abstract: The dispersion of the A-valence-band in GaN has been deduced from the observation of high-index magnetoexcitonic states in polarized interband magnetoreflectivity and is found to be strongly nonparabolic with a mass in the range 1.2-1.8m(e). It matches the theory of Kim et al. [Phys. Rev. B 56, 7363 (1997)] extremely well, which also gives a strong k-dependent A-valence-band mass. A strong phonon coupling leads to quenching of the observed transitions at about an LO-phonon energy above the band gap and a strong nonparabolicity. The valence band was deduced from subtracting from the reduced dispersion the electron contribution with a model that includes a full treatment of the electron-phonon interaction.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 13
DOI: 10.1103/PhysRevB.64.081203
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“Non-homogeneous magnetic field induced magnetic edge states and their transport in a quantum wire”. Badalyan SM, Peeters FM, Physical review : B : condensed matter and materials physics 64, 155303 (2001). http://doi.org/10.1103/PhysRevB.64.155303
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 24
DOI: 10.1103/PhysRevB.64.155303
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“Spin-polarized tunneling through a diluted magnetic semiconductor quantum dot”. Chang K, Chan KS, Peeters FM, Physical review : B : condensed matter and materials physics 71, 155309 (2005). http://doi.org/10.1103/PhysRevB.71.155309
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 15
DOI: 10.1103/PhysRevB.71.155309
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“Electron wave-function spillover in self-assembled InAs/InP quantum wires”. Maes J, Hayne M, Sidor Y, Partoens B, Peeters FM, González Y, González L, Fuster D, Garcia JM, Moshchalkov VV, Physical review : B : condensed matter and materials physics 70, 155311 (2004). http://doi.org/10.1103/PhysRevB.70.155311
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 43
DOI: 10.1103/PhysRevB.70.155311
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“Anisotropic exciton Stark shift in black phosphorus”. Chaves A, Low T, Avouris P, Çakir D, Peeters FM, Physical review : B : condensed matter and materials physics 91, 155311 (2015). http://doi.org/10.1103/PhysRevB.91.155311
Abstract: We calculate the excitonic spectrum of few-layer black phosphorus by direct diagonalization of the effective mass Hamiltonian in the presence of an applied in-plane electric field. The strong attractive interaction between electrons and holes in this system allows one to investigate the Stark effect up to very high ionizing fields, including also the excited states. Our results show that the band anisotropy in black phosphorus becomes evident in the direction-dependent field-induced polarizability of the exciton.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 88
DOI: 10.1103/PhysRevB.91.155311
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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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“Few-electron eigenstates of concentric double quantum rings”. Szafran B, Peeters FM, Physical review : B : condensed matter and materials physics 72, 155316 (2005). http://doi.org/10.1103/PhysRevB.72.155316
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 70
DOI: 10.1103/PhysRevB.72.155316
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“Correlation between electrons and vortices in quantum dots”. Tavernier MB, Anisimovas E, Peeters FM, Physical review : B : condensed matter and materials physics 70, 155321 (2004). http://doi.org/10.1103/PhysRevB.70.155321
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 26
DOI: 10.1103/PhysRevB.70.155321
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“Quantum rings as electron spin beam splitters”. Földi P, Kálmán O, Benedict MG, Peeters FM, Physical review : B : condensed matter and materials physics 73, 155325 (2006). http://doi.org/10.1103/PhysRevB.73.155325
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 145
DOI: 10.1103/PhysRevB.73.155325
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“High-field magnetoexcitons in unstrained GaAs/AlxGa1-xAs quantum dots”. Sidor Y, Partoens B, Peeters FM, Schildermans N, Hayne M, Moshchalkov VV, Rastelli A, Schmidt OG, Physical review : B : condensed matter and materials physics 73, 155334 (2006). http://doi.org/10.1103/PhysRevB.73.155334
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 50
DOI: 10.1103/PhysRevB.73.155334
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“Spin-dependent magnetotransport through a ring due to spin-orbit interaction”. Molnár B, Peeters FM, Vasilopoulos P, Physical review : B : condensed matter and materials physics 69, 155335 (2004). http://doi.org/10.1103/PhysRevB.69.155335
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 199
DOI: 10.1103/PhysRevB.69.155335
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“Bilayer graphene with single and multiple electrostatic barriers: band structure and transmission”. Barbier M, Vasilopoulos P, Peeters FM, Pereira JM, Physical review : B : solid state 79, 155402 (2009). http://doi.org/10.1103/PhysRevB.79.155402
Abstract: We evaluate the electronic transmission and conductance in bilayer graphene through a finite number of potential barriers. Further, we evaluate the dispersion relation in a bilayer graphene superlattice with a periodic potential applied to both layers. As a model we use the tight-binding Hamiltonian in the continuum approximation. For zero bias the dispersion relation shows a finite gap for carriers with zero momentum in the direction parallel to the barriers. This is in contrast to single-layer graphene where no such gap was found. A gap also appears for a finite bias. Numerical results for the energy spectrum, conductance, and the density of states are presented and contrasted with those pertaining to single-layer graphene.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 74
DOI: 10.1103/PhysRevB.79.155402
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“Electronic properties of triangular and hexagonal MoS2 quantum dots”. Pavlović, S, Peeters FM, Physical review : B : condensed matter and materials physics 91, 155410 (2015). http://doi.org/10.1103/PhysRevB.91.155410
Abstract: Using the tight-binding approach, we calculate the electronic structure of triangular and hexagonal MoS2 quantum dots. Due to the orbital asymmetry we show that it is possible to form quantum dots with the same shape but having different electronic properties. The electronic states of triangular and hexagonal quantum dots are explored, as well as the local and total density of states and the convergence towards the bulk spectrum with dot size is investigated. Our calculations show that: (1) edge states appear in the band gap, (2) that there are a larger number of electronic states in the conduction band as compared to the valence band, and (3) the relative number of edge states decreases with increasing dot size.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 44
DOI: 10.1103/PhysRevB.91.155410
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“Intrinsic magnetism in penta-hexa-graphene: A first-principles study”. Aierken Y, Leenaerts O, Peeters FM, Physical review B 94, 155410 (2016). http://doi.org/10.1103/PHYSREVB.94.155410
Abstract: Recently, several monolayer carbon allotropes have been proposed. The magnetic properties of these metal-free materials are investigated, and we explore a special type of all carbon system having an intrinsic magnetic ground state. The structure is composed of mixing pentagonal and hexagonal rings of carbon atoms, such that the unit cell consists of eleven atoms, where two C atoms each have an unpaired electron each with a local magnetic moment. The antiferromagnetic (AFM) state has a lower energy than the ferromagnetic (FM) one. However, a strain-driven transition to the FM ground state is possible. The application of strain not only lowers the energy of the FM state but it also induces an energy barrier of about 13 meV/(magnetic atom) to protect the FM state from excitation. Our findings based on first-principles calculations will motivate other works on similar metal-free magnetic monolayer materials and will have an impact on their possible applications in spintronic devices.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 13
DOI: 10.1103/PHYSREVB.94.155410
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“Lattice dynamics in Sn nanoislands and cluster-assembled films”. Houben K, Couet S, Trekels M, Menendez E, Peissker T, Seo JW, Hu MY, Zhao JY, Alp EE, Roelants S, Partoens B, Milošević, MV, Peeters FM, Bessas D, Brown SA, Vantomme A, Temst K, Van Bael MJ, Physical review B 95, 155413 (2017). http://doi.org/10.1103/PHYSREVB.95.155413
Abstract: To unravel the effects of phonon confinement, the influence of size and morphology on the atomic vibrations is investigated in Sn nanoislands and cluster-assembled films. Nuclear resonant inelastic x-ray scattering is used to probe the phonon densities of states of the Sn nanostructures which show significant broadening of the features compared to bulk phonon behavior. Supported by ab initio calculations, the broadening is attributed to phonon scattering and can be described within the damped harmonic oscillator model. Contrary to the expectations based on previous research, the appearance of high-energy modes above the cutoff energy is not observed. From the thermodynamic properties extracted from the phonon densities of states, it was found that grain boundary Sn atoms are bound by weaker forces than bulk Sn atoms.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 5
DOI: 10.1103/PHYSREVB.95.155413
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“Electronic states in an atomistic carbon quantum dot patterned in graphene”. Craco L, Carara SS, da Silva Pereira TA, Milošević, MV, Physical review B 93, 155417 (2016). http://doi.org/10.1103/PhysRevB.93.155417
Abstract: We reveal the emergence of metallicKondo clouds in an atomistic carbon quantum dot, realized as a single-atom junction in a suitably patterned graphene nanoflake. Using density functional dynamical mean-field theory (DFDMFT) we show how correlation effects lead to striking features in the electronic structure of our device, and how those are enhanced by the electron-electron interactions when graphene is patterned at the atomistic scale. Our setup provides a well-controlled environment to understand the principles behind the orbital-selective Kondo physics and the interplay between orbital and spin degrees of freedom in carbon-based nanomaterials, which indicate new pathways for spintronics in atomically patterned graphene.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 6
DOI: 10.1103/PhysRevB.93.155417
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“Tuning the electronic properties of gated multilayer phosphorene : a self-consistent tight-binding study”. Li LL, Partoens B, Peeters FM, Physical review B 97, 155424 (2018). http://doi.org/10.1103/PHYSREVB.97.155424
Abstract: By taking account of the electric-field-induced charge screening, a self-consistent calculation within the framework of the tight-binding approach is employed to obtain the electronic band structure of gated multilayer phosphorene and the charge densities on the different phosphorene layers. We find charge density and screening anomalies in single-gated multilayer phosphorene and electron-hole bilayers in dual-gated multilayer phosphorene. Due to the unique puckered lattice structure, both intralayer and interlayer charge screenings are important in gated multilayer phosphorene. We find that the electric-field tuning of the band structure of multilayer phosphorene is distinctively different in the presence and absence of charge screening. For instance, it is shown that the unscreened band gap of multilayer phosphorene decreases dramatically with increasing electric-field strength. However, in the presence of charge screening, the magnitude of this band-gap decrease is significantly reduced and the reduction depends strongly on the number of phosphorene layers. Our theoretical results of the band-gap tuning are compared with recent experiments and good agreement is found.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 26
DOI: 10.1103/PHYSREVB.97.155424
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“Electronic properties of bilayer phosphorene quantum dots in the presence of perpendicular electric and magnetic fields”. Li LL, Moldovan D, Xu W, Peeters FM, Physical review B 96, 155425 (2017). http://doi.org/10.1103/PHYSREVB.96.155425
Abstract: Using the tight-binding approach, we investigate the electronic properties of bilayer phosphorene (BLP) quantum dots (QDs) in the presence of perpendicular electric and magnetic fields. Since BLP consists of two coupled phosphorene layers, it is of interest to examine the layer-dependent electronic properties of BLP QDs, such as the electronic distributions over the two layers and the so-produced layer-polarization features, and to see how these properties are affected by the magnetic field and the bias potential. We find that in the absence of a bias potential only edge states are layer polarized while the bulk states are not, and the layer-polarization degree (LPD) of the unbiased edge states increases with increasing magnetic field. However, in the presence of a bias potential both the edge and bulk states are layer polarized, and the LPD of the bulk (edge) states depends strongly (weakly) on the interplay of the bias potential and the interlayer coupling. At high magnetic fields, applying a bias potential renders the bulk electrons in a BLP QD to be mainly distributed over the top or bottom layer, resulting in layer-polarized bulk Landau levels (LLs). In the presence of a large bias potential that can drive a semiconductor-to-semimetal transition in BLP, these bulk LLs exhibit different magnetic-field dependences, i.e., the zeroth LLs exhibit a linearlike dependence on the magnetic field while the other LLs exhibit a square-root-like dependence.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 28
DOI: 10.1103/PHYSREVB.96.155425
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“Partially hydrogenated and fluorinated graphene : structure, roughness, and negative thermal expansion”. Neek-Amal M, Peeters FM, Physical review : B : condensed matter and materials physics 92, 155430 (2015). http://doi.org/10.1103/PhysRevB.92.155430
Abstract: The structural properties of partially hydrogenated and fluorinated graphene with different percentages of H/F atoms are investigated using molecular dynamics simulations based on reactive force field (ReaxFF) potentials. We found that the roughness of graphene varies with the percentage (p) of H or F and in both cases is maximal around p = 50%. Similar results were obtained for partially oxidized graphene. The two-dimensional area size of partially fluorinated and hydrogenated graphene exhibits a local minimum around p = 35% coverage. The lattice thermal contraction in partially functionalized graphene is found to be one order of magnitude larger than that of fully covered graphene. We also show that the armchair structure for graphene oxide (similar to the structure of fully hydrogenated and fluorinated graphene) is unstable. Our results show that the structure of partially functionalized graphene changes nontrivially with the C : H and C : F ratio as well as with temperature.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 5
DOI: 10.1103/PhysRevB.92.155430
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“Infrared to terahertz optical conductivity of n-type and p-type monolayer MoS2 in the presence of Rashba spin-orbit coupling”. Xiao YM, Xu W, Van Duppen B, Peeters FM, Physical review B 94, 155432 (2016). http://doi.org/10.1103/PHYSREVB.94.155432
Abstract: We investigate the effect of Rashba spin-orbit coupling (SOC) on the optoelectronic properties of n- and p-type monolayer MoS2. The optical conductivity is calculated within the Kubo formalism. We find that the spin-flip transitions enabled by the Rashba SOC result in a wide absorption window in the optical spectrum. Furthermore, we evaluate the effects of the polarization direction of the radiation, temperature, carrier density, and the strength of the Rashba spin-orbit parameter on the optical conductivity. We find that the position, width, and shape of the absorption peak or absorption window can be tuned by varying these parameters. This study shows that monolayer MoS2 can be a promising tunable optical and optoelectronic material that is active in the infrared to terahertz spectral range.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 20
DOI: 10.1103/PHYSREVB.94.155432
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“Formation and stability of point defects in monolayer rhenium disulfide”. Horzum S, Çakir D, Suh J, Tongay S, Huang Y-S, Ho C-H, Wu J, Sahin H, Peeters FM, Physical review : B : condensed matter and materials physics 89, 155433 (2014). http://doi.org/10.1103/PhysRevB.89.155433
Abstract: Recently, rhenium disulfide (ReS2) monolayers were experimentally extracted by conventional mechanical exfoliation technique from as-grown ReS2 crystals. Unlike the well-known members of transition metal dichalcogenides (TMDs), ReS2 crystallizes in a stable distorted-1T structure and lacks an indirect to direct gap crossover. Here we present an experimental and theoretical study of the formation, energetics, and stability of the most prominent lattice defects in monolayer ReS2. Experimentally, irradiation with 3-MeV He+2 ions was used to break the strong covalent bonds in ReS2 flakes. Photoluminescence measurements showed that the luminescence from monolayers is mostly unchanged after highly energetic a particle irradiation. In order to understand the energetics of possible vacancies in ReS2 we performed systematic first-principles calculations. Our calculations revealed that the formation of a single sulfur vacancy has the lowest formation energy in both Re and S rich conditions and a random distribution of such defects are energetically more preferable. Sulfur point defects do not result in any spin polarization whereas the creation of Re-containing point defects induce magnetization with a net magnetic moment of 1-3 mu B. Experimentally observed easy formation of sulfur vacancies is in good agreement with first-principles calculations.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 130
DOI: 10.1103/PhysRevB.89.155433
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“Quasibound states of Schrödinger and Dirac electrons in a magnetic quantum dot”. Masir MR, Matulis A, Peeters FM, Physical review : B : solid state 79, 155451 (2009). http://doi.org/10.1103/PhysRevB.79.155451
Abstract: The properties of a two-dimensional electron are investigated in the presence of a circular step magnetic-field profile. Both electrons with parabolic dispersion as well as Dirac electrons with linear dispersion are studied. We found that in such a magnetic quantum dot no electrons can be confined. Nevertheless close to the Landau levels quasibound states can exist with a rather long lifetime.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 55
DOI: 10.1103/PhysRevB.79.155451
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“Strong three-level resonant magnetopolaron effect due to the intersubband coupling in heavily modulation-doped GaAs/AlxGa1-xAs single quantum wells at high magnetic-fields”. Wang YJ, Leem YA, McCombe BD, Wu XG, Peeters FM, Jones ED, Reno JR, Lee XY, Jiang HW, Physical Review B 64, 161303 (2001). http://doi.org/10.1103/PhysRevB.64.161303
Abstract: Electron cyclotron resonance CR) measurements have been carried out in magnetic fields up to 32 T to study electron-phonon interaction in two heavily modulation-delta -doped GaAs/Al0.3Ga0.7As single-quantum-well samples. No measurable resonant magnetopolaron effects were observed in either sample in the region of the GaAs longitudinal optical (LO) phonons. However, when the CR frequency is above LO phonon frequency, omega (LO)=E-LO/(h) over bar, at high magnetic fields (B>27 T), electron CR exhibits a strong avoided-level-crossing splitting for both samples at frequencies close to (omega (LO)+ (E-2-E-1)1 (h) over bar, where E-2, and E-1 are the energies of the bottoms of the second and the first subbands, respectively. The energy separation between the two branches is large with the minimum separation of 40 cm(-1) occurring at around 30.5 T. A detailed theoretical analysis, which includes a self-consistent calculation of the band structure and the effects of electron-phonon interaction on the CR, shows that this type of splitting is due to a three-level resonance between the second Landau level of the first electron subband and the lowest Landau level of the second subband plus one GaAs LO phonon. The absence of occupation effects in the final states and weak screening or this three-level process yields large energy separation even in the presence of high electron densities. Excellent agreement between the theory and the experimental results is obtained.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 7
DOI: 10.1103/PhysRevB.64.161303
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“Electric-field-driven Mott metal-insulator transition in correlated thin films : an inhomogeneous dynamical mean-field theory approach”. Bakalov P, Esfahani DN, Covaci L, Peeters FM, Tempere J, Locquet J-P, Physical review : B : condensed matter and materials physics 93, 165112 (2016). http://doi.org/10.1103/PhysRevB.93.165112
Abstract: Simulations are carried out based on the dynamical mean-field theory (DMFT) in order to investigate the properties of correlated thin films for various values of the chemical potential, temperature, interaction strength, and applied transverse electric field. Application of a sufficiently strong field to a thin film at half filling leads to the appearance of conducting regions near the surfaces of the film, whereas in doped slabs the application of a field leads to a conductivity enhancement on one side of the film and a gradual transition to the insulating state on the opposite side. In addition to the inhomogeneous DMFT, a local density approximation (LDA) is considered in which the particle density n, quasiparticle residue Z, and spectral weight at the Fermi level A(ω=0) of each layer are approximated by a homogeneous bulk environment. A systematic comparison between the two approaches reveals that the less expensive LDA results are in good agreement with the DMFT approach, except close to the metal-to-insulator transition points and in the layers immediately at the film surfaces. LDA values for n are overall more reliable than those for Z and A(ω=0). The hysteretic behavior (memory effect) characteristic of the bulk doping driven Mott transition persists in the slab.
Keywords: A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 5
DOI: 10.1103/PhysRevB.93.165112
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“Orientational charge density waves and the metal-insulator transition in polymerized KC60”. Verberck B, Nikolaev AV, Michel KH, Physical review : B : condensed matter and materials physics 71, 165117 (2005). http://doi.org/10.1103/PhysRevB.71.165117
Abstract: A theoretical model is presented for the description of the metal-insulator transition which accompanies the structural phase transition at T approximate to 50 K in polymerized KC60. The model involves orientational charge density waves (along the C-60 polymer chains) which were introduced previously for a description of the structural phase transition. A satisfactory qualitative and quantitative understanding is obtained when the three-dimensionality of the crystal and the presence of the K+ counterions is properly taken into account.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 1
DOI: 10.1103/PhysRevB.71.165117
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“Attracting shallow donors : hydrogen passivation in (Al,Ga,In)-doped ZnO”. Matsubara M, Amini MN, Saniz R, Lamoen D, Partoens B, Physical review : B : condensed matter and materials physics 86, 165207 (2012). http://doi.org/10.1103/PhysRevB.86.165207
Abstract: The hydrogen interstitial and the substitutional AlZn, GaZn, and InZn are all shallow donors in ZnO and lead to n-type conductivity. Although shallow donors are expected to repel each other, we show by first-principles calculations that in ZnO these shallow donor impurities attract and form a complex, leading to a donor level deep in the band gap. This puts a limit on the n-type conductivity of (Al,Ga,In)-doped ZnO in the presence of hydrogen.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 7
DOI: 10.1103/PhysRevB.86.165207
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