The influence of the Rashba field on the current-induced domain wall dynamics: A full micromagnetic analysis, including surface roughness and thermal effects
Eduardo Martinez
A micromagnetic study is carried out to analyze the influence of the spin-orbit Rashba field on the current-driven domain wall dynamics along a ferromagnetic strip with high perpendicular magnetocrystalline anisotropy, taking into account both surface roughness and thermal effects. Similarly to the ... [J. Appl. Phys. 111, 07D302 (2012)] published Mon Feb 13, 2012.
Non-Hermitian exciton dynamics in a photosynthetic unit system
A. Thilagam
The non-Hermitian quantum dynamics of excitonic energy transfer in photosynthetic systems is investigated using a dissipative two-level dimer model. The approach is based on Green's function formalism which permits consideration of decoherence and intersite transfer processes on comparable terms. Th ... [J. Chem. Phys. 136, 065104 (2012)] published Mon Feb 13, 2012.
Iron-phthalocyanine molecular junction with high spin filter efficiency and negative differential resistance
Jing Huang, Ke Xu, Shulai Lei, Haibin Su, Shangfeng Yang et al.
We investigate the spin transport properties of iron-phthalocyanine (FePc) molecule sandwiched between two N-doped graphene nanoribbons (GNRs) based on the density functional theory and nonequilibrium Green's function methods. Our calculated results clearly reveal that the FePc molecular junction ha ... [J. Chem. Phys. 136, 064707 (2012)] published Mon Feb 13, 2012.
A reconstruction of cubic rs-ZnO on MgO (200) substrate through (100) plane of w-ZnO:rs-ZnO for transparent electronic application
Santosh M. Bobade
ZnO crystallizes in various crystallographic forms. While, the zinc blende (zb) and the rock salt (rs) structure of ZnO occur at high pressure, wurtzite (w) ZnO is the observed structure under ambient conditions. Interestingly, the high pressure polymorph of ZnO, cubic rs-ZnO oxide is presented on M ... [Appl. Phys. Lett. 100, 072102 (2012)] published Mon Feb 13, 2012.
Conduction band structure in wurtzite GaAs nanowires: A resonant Raman scattering study
Wang Peng, F. Jabeen, B. Jusserand, J. C. Harmand, and M. Bernard
We report on a room temperature Raman resonance at 1.56 eV in GaAs wurtzite nanowires together with the emergence of a strong forbidden longitudinal optical phonon line. We attribute this resonance, absent in zinc blende wires with similar diameters, to an additional excitonic transition due to cond ... [Appl. Phys. Lett. 100, 073102 (2012)] published Mon Feb 13, 2012.
Sign change in the organic magnetoresistance of tris(8-hydroxyquinolinato)aluminum upon annealing
Hoju Kang, Ik-Jae Lee, and Choon Sup Yoon
We report the sign change in the magnetoresistance of a tris(8-hydroxyquinolinato)aluminum film with the morphological change from amorphous to crystalline state upon annealing. The negative component of the magnetoresistance followed power law behavior, whereas the positive one showed non-Lorentzia ... [Appl. Phys. Lett. 100, 073302 (2012)] published Mon Feb 13, 2012.
Response to Comment on `Forming-free resistive switching in NdO, DyO, and ErO films fabricated in full room temperature' [Appl. Phys. Lett. 100, 076101 (2012)]
Tung-Ming Pan and Chih-Hung Lu
Abstract not available. [Appl. Phys. Lett. 100, 076102 (2012)] published Mon Feb 13, 2012.
Circulating currents in a metallic ring with two quantum dots
E. V. Anda, G. Chiappe, and E. Louis
We analyze a system constituted by two single level quantum dots embedded in a metallic ring connected to external electrodes. The energy levels of the dots are controlled by an external gate potential. Additionally, the external electrodes are under the effect of an external applied potential. In t ... [J. Appl. Phys. 111, 033711 (2012)] published Mon Feb 13, 2012.
NMR Probing of the Spin Polarization of the nu=5/2 Quantum Hall State
M. Stern, B. A. Piot, Y. Vardi, V. Umansky, P. Plochocka et al.
Resistively detected nuclear magnetic resonance is used to measure the Knight shift of the As nuclei and determine the electron spin polarization of the fractional quantum Hall states of the second Landau level. We show that the 5/2 state is fully polarized within experimental error, thus confirming ... [Phys. Rev. Lett. 108, 066810 ] published .
Fermi-Level Tuning of Epitaxial SbTe Thin Films on Graphene by Regulating Intrinsic Defects and Substrate Transfer Doping
Yeping Jiang, Y. Y. Sun, Mu Chen, Yilin Wang, Zhi Li et al.
High-quality SbTe films are obtained by molecular beam epitaxy on a graphene substrate and investigated by in situ scanning tunneling microscopy and spectroscopy. Intrinsic defects responsible for the natural p-type conductivity of SbTe are identified to be the Sb vacancies and Sb antisites in agree ... [Phys. Rev. Lett. 108, 066809 ] published .
Spin-Polarized Dirac-Cone-Like Surface State with d Character at W(110)
K. Miyamoto, A. Kimura, K. Kuroda, T. Okuda, K. Shimada et al.
The surface of W(110) exhibits a Dirac-cone-like state with d character within a spin-orbit-induced symmetry gap. As a function of the wave vector parallel to the surface, it shows a nearly massless energy dispersion and a pronounced spin polarization, which is antisymmetric with respect to the Bril ... [Phys. Rev. Lett. 108, 066808 ] published .
Large Conductance Modulation of Gold Thin Films by Huge Charge Injection via Electrochemical Gating
D. Daghero, F. Paolucci, A. Sola, M. Tortello, G. A. Ummarino et al.
By using an electrochemical gating technique with a new combination of polymer and electrolyte, we were able to inject surface charge densities n as high as 3.5 x 10 e/cm in gold films and to observe large relative variations in the film resistance, DeltaR/R, up to 10% at low temperature. DeltaR/R ... [Phys. Rev. Lett. 108, 066807 ] published .
Superconducting Pairs with Extreme Uniaxial Anisotropy in URuSi
M. M. Altarawneh, N. Harrison, G. Li, L. Balicas, P. H. Tobash et al.
We report magnetic field orientation-dependent measurements of the superconducting upper critical field in high quality single crystals of URuSi and find the effective g factor estimated from the Pauli limit to agree remarkably well with that found in quantum oscillation experiments, both quantitati ... [Phys. Rev. Lett. 108, 066407 ] published .
Non-Kondo Mechanism for Resistivity Minimum in Spin Ice Conduction Systems
Masafumi Udagawa, Hiroaki Ishizuka, and Yukitoshi Motome
We present a mechanism of resistivity minimum in conduction electron systems coupled with localized moments, which is distinguished from the Kondo effect. Instead of the spin-flip process in the Kondo effect, electrons are elastically scattered by local spin correlations which evolve in a particular ... [Phys. Rev. Lett. 108, 066406 ] published .
Single-Ion Kondo Scaling of the Coherent Fermi Liquid Regime in CeLaNiGe
Adam P. Pikul, Ulrike Stockert, Alexander Steppke, Tomasz Cichorek, Stefanie Hartmann et al.
Thermodynamic and transport properties of the La-diluted Kondo lattice CeNiGe were studied in a wide temperature range. The Ce-rich alloys CeLaNiGe were found to exhibit distinct features of the coherent heavy Fermi liquid. At intermediate compositions (0.7<=x<=0.9), non-Fermi liquid properties have ... [Phys. Rev. Lett. 108, 066405 ] published .
Observation of linear solid-solid phase transformation in silicon nanoparticles
Kevin Mantey, Aiping Zhu, Jack Boparai, Munir Nayfeh, Charles Marsh et al.
In bulk single-crystal silicon, the semiconducting diamond-to-metallic ss-Sn phase transformation nucleates on defects, and is manifested by a sharp uptake in light absorption at a threshold of ~11 Gpa, accompanied with the creation of nanosized (2050 nm) fragmentation domains. We report on the obse ... [Phys. Rev. B 85, 085417 ] published .
Evidence for the formation of quasibound states in an asymmetrical quantum point contact
Phillip M. Wu, Peng Li, Hao Zhang, and A. M. Chang
Features below the first conductance plateau in ballistic quantum point contacts (QPCs) are often ascribed to electron interaction and spin effects within the single mode limit. In QPCs with a highly asymmetric geometry, we observe sharp resonance peaks when the point contacts are gated to the singl ... [Phys. Rev. B 85, 085305 ] published .
Isospin of topological defects in Dirac systems
Igor F. Herbut
We study the Dirac quasiparticles in d-dimensional lattice systems of electrons in the presence of domain walls (d=1), vortices (d=2), or hedgehogs (d=3) of superconducting and/or insulating, order parameters, which appear as mass terms in the Dirac equation. Such topological defects have been known ... [Phys. Rev. B 85, 085304 ] published .
Fermi surface reconstruction in CeTe induced by charge density waves investigated via angle resolved photoemission
J.-S. Kang, D. H. Kim, H. J. Lee, Jihoon Hwang, Han-Koo Lee et al.
Electronic structures of a charge-density wave (CDW) system CeTeSb (x=0, 0.05) have been investigated by employing angle-resolved photoemission spectroscopy (ARPES) and the first-principles electronic and phonon band-structure methods. The observed Fermi surface (FS) agrees very well with the calcul ... [Phys. Rev. B 85, 085104 ] published .
Strain dependence of bonding and hybridization across the metal-insulator transition of VO
J. Laverock, L. F. J. Piper, A. R. H. Preston, B. Chen, J. McNulty et al.
Soft x-ray spectroscopy is used to investigate the strain dependence of the metal-insulator transition of VO. Changes in the strength of the V 3dO 2p hybridization are observed across the transition and are linked to the structural distortion. Furthermore, although the V-V dimerization is well descr ... [Phys. Rev. B 85, 081104 ] published .
Resonant polaron-assisted tunneling of strongly interacting electrons through a single-level vibrating quantum dot
Gleb A. Skorobagatko
The problem of resonant transport of strongly interacting electrons through a one-dimensional single-level vibrating quantum dot is being considered. In this paper, we generalize the Komnik and Gogolin model [Phys. Rev. Lett. 90, 246403 (2003)] for the single-electron transistor with g=1/2 Luttinger ... [Phys. Rev. B 85, 075310 ] published .
Energy relaxation at quantum Hall edge
Ivan P. Levkivskyi and Eugene V. Sukhorukov
In this work, we address the recent experiments [C. Altimiras et al., Nat. Phys. 6, 34 (2010); H. le Sueur et al., Phys. Rev. Lett. 105, 056803 (2010);C. Altimiras et al., Phys. Rev. Lett. 105, 226804 (2010)], where an electron distribution function at the quantum Hall (QH) edge at filling factor nu ... [Phys. Rev. B 85, 075309 ] published .
Quantum criticality of the sub-Ohmic spin-boson model
Stefan Kirchner, Kevin Ingersent, and Qimiao Si
We revisit the critical behavior of the sub-Ohmic spin-boson model. Analysis of both the leading and subleading terms in the temperature dependence of the inverse static local spin susceptibility at the quantum critical point, calculated using a numerical renormalization-group method, provides evide ... [Phys. Rev. B 85, 075113 ] published .
Thermoelectric properties of the electron-doped perovskites SrCaTiNbO
J. Fukuyado, K. Narikiyo, M. Akaki, H. Kuwahara, and T. Okuda
We have investigated thermoelectric (TE) properties for single crystals of perovskites SrCaTiNbO for 0 <= x <= 0.4 and 0 <= y <= 0.03 below room temperature (RT). We found that SrTiNbO shows a large power factor at low temperature (PF=50 [mu]W/K cm at 100 K ~ 90 [mu]W/K cm at 50 K) and the largest d ... [Phys. Rev. B 85, 075112 ] published .
Spin accumulation created electrically in an n-type germanium channel using Schottky tunnel contacts
K. Kasahara, Y. Baba, K. Yamane, Y. Ando, S. Yamada et al.
Using high-quality FeSi/n-Ge Schottky-tunnel-barrier contacts, we study spin accumulation in an n-type germanium (n-Ge) channel. In the three- or two-terminal voltage measurements with low bias current conditions at 50 K, Hanle-effect signals are clearly detected only at a forward-biased contact. Th ... [J. Appl. Phys. 111, 07C503 (2012)] published Fri Feb 10, 2012.
Spin-flip effect on transport properties of a Mn molecule
Hua Hao, XiaoHong Zheng, RuiNing Wang, Zhi Zeng, and H. Q. Lin
Electron transport through a single-molecule magnet [NEt][MnZn(salox)O(N)Cl] is investigated by spin-polarized density functional theory combined with the Keldysh nonequilibrium Green's function technique. Our study demonstrates that spin-filtering effect and negative differential resistance exist i ... [J. Appl. Phys. 111, 07B303 (2012)] published Fri Feb 10, 2012.
Resonantly enhanced optical nonlinearity in hybrid semiconductor quantum dot metal nanoparticle structures
Ming Fu, Kai Wang, Hua Long, Guang Yang, Peixiang Lu et al.
The optical nonlinearity of hybrid structures composed of CdTe quantum dots and periodical particle array of gold is studied using Z-scan method. The optical nonlinearity is dramatically affected by the interaction between exciton in CdTe quantum dots and surface plasmons in Au periodical particle a ... [Appl. Phys. Lett. 100, 063117 (2012)] published Fri Feb 10, 2012.
Transparent conductive thin films of single-wall carbon nanotubes encapsulating dopant molecules
Naoki Kishi, Ikuma Miwa, Toshiya Okazaki, Takeshi Saito, Toshihisa Mizutani et al.
Transparent conductive thin films of single-wall carbon nanotubes (SWCNTs) doped with organic dopant molecules encapsulated inside the SWCNTs are reported. Doping with tetrafluorotetracyano-p-quinodimethane encapsulated within the SWCNTs improved the ratio of direct current to optical conductivity i ... [Appl. Phys. Lett. 100, 063121 (2012)] published Fri Feb 10, 2012.
Epitaxial NiO gate dielectric on AlGaN/GaN heterostructures
Fabrizio Roccaforte, Giuseppe Greco, Patrick Fiorenza, Vito Raineri, Graziella Malandrino et al.
This letter reports on epitaxial nickel oxide (NiO) films grown by metal-organic chemichal vapor deposition on AlGaN/GaN heterostructures. The grown material was epitaxial, free from voids and exhibited a permittivity of 11.7, close to bulk NiO. This approach is advantageous with respect other metho ... [Appl. Phys. Lett. 100, 063511 (2012)] published Fri Feb 10, 2012.
Electronic states and the influence of oxygen addition on the optical absorption behaviour of manganese phthalocyanine
R. Friedrich, T. Hahn, J. Kortus, M. Fronk, F. Haidu et al.
The effects of electronic states and air exposure on the spectroscopic properties of manganese phthalocyanine (MnPc) have been examined. The observed features of the Q-band in the absorption spectra can be explained by intrinsic electronic properties of MnPc, i.e., the formation of singly charged mo ... [J. Chem. Phys. 136, 064704 (2012)] published Fri Feb 10, 2012.
Hierarchical Nature of the Quantum Hall Effects
Parsa Bonderson
I demonstrate that the wave function for a nu=n+nu-tilde quantum Hall state with Landau levels 0,1,…,n-1 filled and a filling fraction nu-tilde quantum Hall state with 0
Hall Viscosity and Electromagnetic Response
Carlos Hoyos and Dam Thanh Son
We show that, for Galilean invariant quantum Hall states, the Hall viscosity appears in the electromagnetic response at finite wave numbers q. In particular, the leading q dependence of the Hall conductivity at small q receives a contribution from the Hall viscosity. The coefficient of the q term in ... [Phys. Rev. Lett. 108, 066805 ] published .
Ir(111) Surface State with Giant Rashba Splitting Persists under Graphene in Air
A. Varykhalov, D. Marchenko, M. R. Scholz, E. D. L. Rienks, T. K. Kim et al.
We reveal a giant Rashba effect (alpha[approximate]1.3 eV A) on a surface state of Ir(111) by angle-resolved photoemission and by density functional theory. It is demonstrated that the existence of the surface state, its spin polarization, and the size of its Rashba-type spin-orbit splitting remain ... [Phys. Rev. Lett. 108, 066804 ] published .
New Perspective on Formation Energies and Energy Levels of Point Defects in Nonmetals
R. Ramprasad, H. Zhu, Patrick Rinke, and Matthias Scheffler
We propose a powerful scheme to accurately determine the formation energy and thermodynamic charge transition levels of point defects in nonmetals. Previously unknown correlations between defect properties and the valence-band width of the defect-free host material are identified allowing for a dete ... [Phys. Rev. Lett. 108, 066404 ] published .
Metal-to-Insulator Transition and Electron-Hole Puddle Formation in Disordered Graphene Nanoribbons
Gerald Schubert and Holger Fehske
The experimentally observed metal-to-insulator transition in hydrogenated graphene is numerically confirmed for actual sized graphene samples and realistic impurity concentrations. The eigenstates of our tight-binding model with substitutional disorder corroborate the formation of electron-hole pudd ... [Phys. Rev. Lett. 108, 066402 ] published .
Metal-dielectric-metal surface plasmon-polariton resonators
Anu Chandran, Edward S. Barnard, Justin S. White, and Mark L. Brongersma
A theoretical study of standing-wave resonances of surface plasmon polaritons (SPPs) in finite-length metal-dielectric-metal cavities is presented. A Fabry-Perot model is constructed to describe the cavity resonances, and the associated optical parameters are calculated analytically. One key paramet ... [Phys. Rev. B 85, 085416 ] published .
Tunneling transport through superconducting wires with Majorana bound states
B. H. Wu and J. C. Cao
We investigate the transport of a topological superconducting wire hosting a pair of Majorana bound states between two normal leads. Both the model-independent scattering matrix theory and the Green's function method for a tight-binding model show that the transport properties are sensitive to the c ... [Phys. Rev. B 85, 085415 ] published .
Symmetry-protected topological phases in noninteracting fermion systems
Xiao-Gang Wen
Symmetry-protected topological (SPT) phases are gapped quantum phases with a certain symmetry, which can all be smoothly connected to the same trivial product state if we break the symmetry. For noninteracting fermion systems with time reversal (T-hat), charge conjugation (C), and/or U(1) (N-hat) sy ... [Phys. Rev. B 85, 085103 ] published .
Hole spin relaxation and coefficients in Landau-Lifshitz-Gilbert equation in ferromagnetic (Ga,Mn)As
K. Shen and M. W. Wu
We investigate the temperature dependence of the coefficients in the Landau-Lifshitz-Gilbert equation in ferromagnetic GaMnAs by employing the Zener model. We first calculate the hole spin relaxation time based on the microscopic kinetic equation. We find that the hole spin relaxation time is typica ... [Phys. Rev. B 85, 075206 ] published .
Competing orders in the Dirac-like electronic structure and the nonlinear sigma model with a topological term
Pouyan Ghaemi and Shinsei Ryu
The Dirac-like electronic structure can host a large number of competing orders in the form of mass terms. In particular, two different order parameters can be said to be dual to each other, when a static defect in one of them traps a quantum number (or charge) of the other. We discuss that such com ... [Phys. Rev. B 85, 075111 ] published .
Interplay of Aharonov-Bohm, chirality, and aspect-ratio effects in the axial conductance of a nanotube
Eugene B. Kolomeisky, Hussain Zaidi, and Joseph P. Straley
A magnetic field applied along the axis of a nanotube can counteract the effect of the tube chirality and dramatically affect its conductance, leading to a way to determine the chirality of a nanotube. The effect of the applied field is strongest in the long tube limit where the conductance is eithe ... [Phys. Rev. B 85, 073404 ] published .
Quarter-filled honeycomb lattice with a quantized Hall conductance
Ganpathy Murthy, Efrat Shimshoni, R. Shankar, and H. A. Fertig
We study a generic two-dimensional hopping model on a honeycomb lattice with strong spin-orbit coupling, without the requirement that the half-filled lattice be a topological insulator. For quarter-(or three-quarter) filling, we show that a state with a quantized Hall conductance generically arises ... [Phys. Rev. B 85, 073103 ] published .
Systematic study of ferroelectric, interfacial, oxidative, and doping effects on conductance of Pt/BaTiO/Pt ferroelectic tunnel junctions
Lei Shen (沈雷), Tiejun Zhou, Zhaoqiang Bai, Minggang Zeng, Jing Qiang Goh et al.
Using the nonequilibrium Green's function method combined with density functional theory, we systematically study the ferroelectric, interfacial, oxidative, and doping effects on electron transport of BaTiO-based ferroelectric tunnel junctions (Pt/BaTiO/Pt). The ferroelectric effect reduces the tunn ... [Phys. Rev. B 85, 064105 ] published .
Dopant effects on solid phase epitaxy in silicon and germanium
B. C. Johnson, T. Ohshima, and J. C. McCallum
The kinetics of dopant-enhanced solid phase epitaxy (SPE) are studied in amorphous silicon (a-Si) and germanium (a-Ge) layers formed by ion implantation. Implanted Sb dopants into a-Ge up to a concentration of 1 x 10cm are considered and compared to As implanted layers at similar concentrations. A ... [J. Appl. Phys. 111, 034906 (2012)] published Thu Feb 9, 2012.
Length dependence of the resistance in graphite: Influence of ballistic transport
P. Esquinazi, J. Barzola-Quiquia, S. Dusari, and N. Garcia
Using a linear array of voltage electrodes with a separation of several micrometers on a 20 nm thick and 30 [mu]m long multigraphene sample, we show that the measured resistance does not follow the usual length dependence according to Ohm's law. The deviations can be quantitatively explained taking ... [J. Appl. Phys. 111, 033709 (2012)] published Thu Feb 9, 2012.
Growth and electrical characterisation of delta-doped boron layers on (111) diamond surfaces
Robert Edgington, Syunsuke Sato, Yuichiro Ishiyama, Richard Morris, Richard B. Jackman et al.
A plasma enhanced chemical vapor deposition protocol for the growth of delta-doping of boron in diamond is presented, using the (111) diamond plane as a substrate for diamond growth. AC Hall effect measurements have been performed on oxygen terminated delta-layers and desirable sheet carrier densiti ... [J. Appl. Phys. 111, 033710 (2012)] published Thu Feb 9, 2012.
Atomic layer deposited (TiO)(AlO)/InGaAs gate stacks for III-V based metal-oxide-semiconductor field-effect transistor applications
C. Mahata, S. Mallik, T. Das, C. K. Maiti, G. K. Dalapati et al.
Atomic layer deposited (ALD) (TiO)(AlO)(TiAlO) alloy gate dielectrics on InGaAs/InP substrates are shown to produce high quality interfaces between TiAlO and InGaAs. The surface morphology and interfacial reaction of nanolaminate ALD TiAlO on InGaAs are studied using atomic force microscopy and x-ra ... [Appl. Phys. Lett. 100, 062905 (2012)] published Thu Feb 9, 2012.
Electronic structures of an epitaxial graphene monolayer on SiC(0001) after metal intercalation (metal = Al, Ag, Au, Pt, and Pd): A first-principles study
Chia-Hsiu Hsu, Wen-Huan Lin, Vidvuds Ozolins, and Feng-Chuan Chuang
The atomic structures and electronic properties of metal-intercalated (metal = Al, Ag, Au, Pt, and Pd) graphene monolayers on SiC(0001) were investigated using first-principles calculations. The unique Dirac cone of graphene near the K point reappeared as the graphite layer was intercalated by these ... [Appl. Phys. Lett. 100, 063115 (2012)] published Thu Feb 9, 2012.
Graphene induced tunability of the surface plasmon resonance
Jing Niu, Young Jun Shin, Youngbin Lee, Jong-Hyun Ahn, and Hyunsoo Yang
Tunability of the surface plasmon resonance wavelength is demonstrated by varying the thickness of AlO spacer layer inserted between the graphene and nanoparticles. By varying the spacer layer thickness from 0.3 to 1.8 nm, the resonance wavelength is shifted from 583 to 566 nm. The shift is due to a ... [Appl. Phys. Lett. 100, 061116 (2012)] published Thu Feb 9, 2012.
Energy band engineering and controlled p-type conductivity of CuAlO thin films by nonisovalent Cu-O alloying
Z. Q. Yao, B. He, L. Zhang, C. Q. Zhuang, T. W. Ng et al.
The electronic band structure and p-type conductivity of CuAlO films were modified via synergistic effects of energy band offset and partial substitution of less-dispersive Cu 3d with Cu 3d orbitals in the valence band maximum by alloying nonisovalent Cu-O with CuAlO host. The Cu-O/CuAlO alloying fi ... [Appl. Phys. Lett. 100, 062102 (2012)] published Thu Feb 9, 2012.
Non-Abelian Braiding of Lattice Bosons
Eliot Kapit, Paul Ginsparg, and Erich Mueller
We report on a numerical experiment in which we use time-dependent potentials to braid non-Abelian quasiparticles. We consider lattice bosons in a uniform magnetic field within the fractional quantum Hall regime, where nu, the ratio of particles to flux quanta, is near 1/2, 1, or 3/2. We introduce t ... [Phys. Rev. Lett. 108, 066802 ] published .
Ground State of the Parallel Double Quantum Dot System
Rok Zitko, Jernej Mravlje, and Kristjan Haule
We resolve the controversy regarding the ground state of the parallel double quantum dot system near half filling. The numerical renormalization group predicts an underscreened Kondo state with residual spin-1/2 magnetic moment, ln2 residual impurity entropy, and unitary conductance, while the Bethe ... [Phys. Rev. Lett. 108, 066602 ] published .
Electric Field Confinement Effect on Charge Transport in Organic Field-Effect Transistors
Xiaoran Li, Andrey Kadashchuk, Ivan I. Fishchuk, Wiljan T. T. Smaal, Gerwin Gelinck et al.
While it is known that the charge-carrier mobility in organic semiconductors is only weakly dependent on the electric field at low fields, the experimental mobility in organic field-effect transistors using silylethynyl-substituted pentacene is found to be surprisingly field dependent at low source- ... [Phys. Rev. Lett. 108, 066601 ] published .
Coherent Emission from a Disordered Organic Semiconductor Induced by Strong Coupling with Surface Plasmons
S. Aberra Guebrou, C. Symonds, E. Homeyer, J. C. Plenet, Yu. N. Gartstein et al.
In this Letter, we show that the strong coupling between a disordered set of molecular emitters and surface plasmons leads to the formation of spatially coherent hybrid states extended on macroscopic distances. Young-type interferometric experiments performed on a system of J-aggregated dyes spread ... [Phys. Rev. Lett. 108, 066401 ] published .
Interplay between interaction and chiral anomaly in the holographic approach
Ki-Seok Kim and Takuya Tsukioka
Strongly coupled conformal field theory appears to describe universal scaling around quantum criticality, where critical exponents reflect the nature of emergent excitations. In particular, novel symmetries can emerge from strong interactions that are expected to be responsible for quantum number fr ... [Phys. Rev. D 85, 045011 ] published .
Electronic structure and magnetic properties of metallocene multiple-decker sandwich nanowires
C. Morari, H. Allmaier, F. Beiuşeanu, T. Jurcut, and L. Chioncel
We present a study of the electronic and magnetic properties of the multiple-decker sandwich nanowires (CP-M) composed of cyclopentadienyl (CP) rings and 3d transition-metal atoms (M = Ti to Ni) using first-principles techniques. We demonstrate using density functional theory that structural relaxat ... [Phys. Rev. B 85, 085413 ] published .
Rashba effect in type-II resonant tunneling diodes enhanced by in-plane magnetic fields
J. Silvano de Sousa and J. Smoliner
In this paper, we adapt the transfer matrix method to calculate the current-voltage curves of type-II GaAsSb/InGaAs resonant tunneling diodes on which a huge Rashba splitting of the current resonances has been reported recently. It is shown that, in transverse magnetic fields, the k distribution of ... [Phys. Rev. B 85, 085303 ] published .
Curvature effects on valley splitting and degeneracy lifting: Case of Si/Ge rolled-up nanotubes
Giovanni Pizzi, Michele Virgilio, Giuseppe Grosso, Suwit Kiravittaya, and Oliver G. Schmidt
We numerically investigate electronic states, degeneracy lifting, and valley splitting in the conduction band of rolled-up Si/Ge nanotubes. Results are derived from a tight-binding model where the input equilibrium positions of the atoms are obtained by means of continuum elasticity theory. We find ... [Phys. Rev. B 85, 075308 ] published .
Decoherence-induced conductivity in the discrete one-dimensional Anderson model: A novel approach to even-order generalized Lyapunov exponents
Matias Zilly, Orsolya Ujsaghy, Marko Woelki, and Dietrich E. Wolf
A recently proposed statistical model for the effects of decoherence on electron transport manifests a decoherence-driven transition from quantum-coherent localized to Ohmic behavior when applied to the one-dimensional Anderson model. Here we derive the resistivity in the Ohmic case and show that th ... [Phys. Rev. B 85, 075110 ] published .
Influence of Coulomb interaction on the Aharonov-Bohm effect in an electronic Fabry-Perot interferometer
Stephane Ngo Dinh and Dmitry A. Bagrets
We study the role of Coulomb interaction in an electronic Fabry-Perot interferometer (FPI) realized with chiral edge states in the integer quantum Hall regime in the limit of weak backscattering. Assuming that a compressible Coulomb island in a bulk region of the FPI is formed, we develop a capacita ... [Phys. Rev. B 85, 073403 ] published .
Pseudogap in the chain states of YBaCuO
V. B. Zabolotnyy, A. A. Kordyuk, D. Evtushinsky, V. N. Strocov, L. Patthey et al.
As established by scanning tunneling microscopy (STM), cleaved surfaces of the high-temperature superconductor YBaCuO develop charge-density wave (CDW) modulations in the one-dimensional (1D) CuO chains. At the same time, no signatures of the CDW have been reported in the spectral function of the ch ... [Phys. Rev. B 85, 064507 ] published .
Field-induced phases in UPtSi
D. Schulze Grachtrup, M. Bleckmann, B. Willenberg, S. Sullow, M. Bartkowiak et al.
The tetragonal compound UPtSi has been characterized as a moderately mass-enhanced system with an antiferromagnetic (AFM) ground state below T=32 K. Here, we present an extensive study of the behavior in high magnetic fields. We have performed pulsed field magnetization and static field resistivity ... [Phys. Rev. B 85, 054410 ] published .
A pancake-shaped nano-aggregate for focusing surface plasmons
Shao Ying Huang, Weng Cho Chew, Yang G. Liu, Bae-Ian Wu, and H. W. Choi
We proposed a pancake-shaped nano-aggregate that highly focuses surface plasmons. The structure is a superposition of bowtie-shaped dimers, where surface plasmons are excited, resonated with the structure, and coupled. Surface integral equation method (Poggio-Miller-Chang-Harrington-Wu-Tsai method) ... [J. Appl. Phys. 111, 034308 (2012)] published Wed Feb 8, 2012.
Quantum confinement in Si and Ge nanostructures
E. G. Barbagiovanni, D. J. Lockwood, P. J. Simpson, and L. V. Goncharova
We apply perturbative effective mass theory as a broadly applicable theoretical model for quantum confinement (QC) in all Si and Ge nanostructures including quantum wells (QWs), wires (Q-wires), and dots (QDs). Within the limits of strong, medium, and weak QC, valence and conduction band edge energy ... [J. Appl. Phys. 111, 034307 (2012)] published Wed Feb 8, 2012.
Properties of single crystalline AZnSb (A = Ca,Eu,Yb)
Andrew F. May, Michael A. McGuire, Jie Ma, Olivier Delaire, Ashfia Huq et al.
Single crystals of CaZnSb, EuZnSb, and YbZnSb were grown from melts of nominal composition AZnSb (A = Ca,Eu,Yb) with the excess melt being removed at 1073 K. The electrical transport properties are consistent with those previously reported for polycrystalline samples. This confirms that the p-type c ... [J. Appl. Phys. 111, 033708 (2012)] published Wed Feb 8, 2012.
High temperature annealing of n-type 4H-SiC: Impact on intrinsic defects and carrier lifetime
Bernd Zippelius, Jun Suda, and Tsunenobu Kimoto
In this paper, the impact of high-temperature annealing of 4H silicon carbide (SiC) on the formation of intrinsic defects, such as Z and EH, and on carrier lifetimes was studied. Four nitrogen-doped epitaxial layers with various initial concentrations of the Z- and EH-centers (10-10cm) were investig ... [J. Appl. Phys. 111, 033515 (2012)] published Wed Feb 8, 2012.
The role of surface defects in multi-exciton generation of lead selenide and silicon semiconductor quantum dots
Heather M. Jaeger, Sean Fischer, and Oleg V. Prezhdo
Multi-exciton generation (MEG), the creation of more than one electron-hole pair per photon absorbed, occurs for excitation energies greater than twice the bandgap (E). Imperfections on the surface of quantum dots, in the form of atomic vacancies or incomplete surface passivation, lead to less than ... [J. Chem. Phys. 136, 064701 (2012)] published Wed Feb 8, 2012.
Microstructure, AC impedance and DC electrical conductivity characteristics of NiFeGdO (x = 0, 0.05 and 0.075)
K. Kamala Bharathi, G. Markandeyulu, and C. V. Ramana
The structure and electrical characteristics of Gd doped Ni ferrite materials, namely NiFeGdO and NiFeGdO are reported to demonstrate their improved electrical properties compared to that of pure NiFeO. NiFeGdO and NiFeGdO compounds crystallize in the cubic inverse spinel phase with a very small amo ... [AIP Advances 2, 012139 (2012)] published Wed Feb 8, 2012.
Triboelectric charging of insulating polymerssome new perspectives
Meurig W. Williams
Tribolectric charging results from contact between surfaces, but precisely what is meant by each is not defined or understood, as they relate to charging. The recent microscopic evidence that contact charging can result from material transfer provides incentive to examine how contact charging is aff ... [AIP Advances 2, 010701 (2012)] published Wed Feb 8, 2012.
Exchange effects on spin-dependent ac transport
Jin Lan, Wen-Quan Sui, and Xuean Zhao
Spin-dependent ac transport problem is studied with exchange effects. Spin-spin exchange interaction and charge-charge Coulomb interaction are included simultaneously to determine the landscape of internal potential and the spin-dependent ac conductance. Gauge invariance and charge conservation are ... [Appl. Phys. Lett. 100, 062405 (2012)] published Wed Feb 8, 2012.
Bethe Ansatz Approach to the Kondo Effect within Density-Functional Theory
Justin P. Bergfield, Zhen-Fei Liu, Kieron Burke, and Charles A. Stafford
Transport through an Anderson junction (two macroscopic electrodes coupled to an Anderson impurity) is dominated by a Kondo peak in the spectral function at zero temperature. We show that the single-particle Kohn-Sham potential of density-functional theory reproduces the linear transport, despite th ... [Phys. Rev. Lett. 108, 066801 ] published .
Accurate description of charge transport in organic field effect transistors using an experimentally extracted density of states
W. S. C. Roelofs, S. G. J. Mathijssen, R. A. J. Janssen, D. M. de Leeuw, and M. Kemerink
The width and shape of the density of states (DOS) are key parameters to describe the charge transport of organic semiconductors. Here we extract the DOS using scanning Kelvin probe microscopy on a self-assembled monolayer field effect transistor (SAMFET). The semiconductor is only a single monolaye ... [Phys. Rev. B 85, 085202 ] published .
Full configuration interaction perspective on the homogeneous electron gas
James J. Shepherd, George Booth, Andreas Gruneis, and Ali Alavi
Highly accurate results for the homogeneous electron gas (HEG) have only been achieved to date within a diffusion Monte Carlo (DMC) framework. Here, we introduce a recently developed stochastic technique, full configuration interaction quantum Monte Carlo (FCIQMC), which samples the exact wave funct ... [Phys. Rev. B 85, 081103 ] published .
Multivalley spin relaxation in n-type bulk GaAs in the presence of high electric fields
H. Tong and M. W. Wu
Multivalley spin relaxation in n-type bulk GaAs in the presence of high electric field is investigated from the microscopic kinetic spin Bloch equation approach with the Gamma and L valleys included. We show that the spin relaxation time decreases monotonically with the electric field, which differs ... [Phys. Rev. B 85, 075203 ] published .
Ground-state degeneracy in the Levin-Wen model for topological phases
Yuting Hu, Spencer D. Stirling, and Yong-Shi Wu
We study the properties of topological phases by calculating the ground-state degeneracy (GSD) of the two-dimensional Levin-Wen (LW) model. Here it is explicitly shown that the GSD depends only on the spatial topology of the system. Then we show that the ground state on a sphere is always nondegener ... [Phys. Rev. B 85, 075107 ] published .
Extended dual description of Mott transition beyond two-dimensional space
Yin Zhong, Ke Liu, and Hong-Gang Luo
Motivated by the recent paper of Mross and Senthil [Phys. Rev. B 84, 165126 (2011)], which provides a dual description for a Mott transition from a Fermi liquid to a quantum-spin liquid in two space dimensions, we extend their approach to higher-dimensional cases, and we provide explicit formalism i ... [Phys. Rev. B 85, 075106 ] published .
Image charge dynamics in time-dependent quantum transport
Petri Myohanen, Riku Tuovinen, Topi Korhonen, Gianluca Stefanucci, and Robert van Leeuwen
In this work, we investigate the effects of the electron-electron interaction between a molecular junction and the metallic leads in time-dependent quantum transport. We employ the recently developed embedded Kadanoff-Baym method [Phys. Rev. B 80, 115107 (2009)] and show that the molecule-lead inter ... [Phys. Rev. B 85, 075105 ] published .
Electronic states in heterostructures with piece-wise uniform Dirac cones
Hai-Yao Deng
We discuss graphene physics that are associated with Fermi velocity rather than bandgap or external potential. Such physics are illustrated with a simple junction that is comprised of two uniform electrodes bridged by a central uniform channel. The main difference between these components is suppose ... [J. Appl. Phys. 111, 033706 (2012)] published Tue Feb 7, 2012.
Metal contact to graphene nanoribbon
Gyungseon Seol and Jing Guo
Metal to graphene nanoribbon (GNR) contact is explored by self-consistent numerical simulations. The Schottky barrier height of the GNR contact can be modulated by either the gate voltage or the workfunction of the metal contact. An Ohmic contact with multiple-subband injection can be achieved with ... [Appl. Phys. Lett. 100, 063108 (2012)] published Tue Feb 7, 2012.
Interplay of point defects, biaxial strain, and thermal conductivity in homoepitaxial SrTiO thin films
S. Wiedigen, T. Kramer, M. Feuchter, I. Knorr, N. Nee et al.
Separating out effects of point defects and lattice strain on thermal conductivity is essential for improvement of thermoelectric properties of SrTiO. We study relations between defects generated during deposition, induced lattice strain, and their impact on thermal conductivity kappa in homoepitaxi ... [Appl. Phys. Lett. 100, 061904 (2012)] published Tue Feb 7, 2012.
Dependence of negative differential resistance on electronic phase separation in unpatterned manganite films
J. F. Ding, K. X. Jin, Z. Zhang, and T. Wu
Here, we report that small but well-defined negative differential resistance (NDR) steps can be observed at critical voltages in unpatterned millimeter-scale manganite films of Pr(CaSr)MnO. We systematically investigate the magneto-transport properties of strained thin films grown on LaAlO and SrTiO ... [Appl. Phys. Lett. 100, 062402 (2012)] published Tue Feb 7, 2012.
Rectifying behaviors induced by BN-doping in trigonal graphene with zigzag edges
X. Q. Deng, Z. H. Zhang, G. P. Tang, Z. Q. Fan, M. Qiu et al.
Based on nonequilibrium Green's functions in combination with density-function theory, the transport properties of trigonal graphenes, with the vertex carbon atom substituted by one phosphorus or boron atom and bounded through a B-N pair, coupled to gold electrodes are investigated. The rectificatio ... [Appl. Phys. Lett. 100, 063107 (2012)] published Tue Feb 7, 2012.
Superconductivity Induced by Longitudinal Ferromagnetic Fluctuations in UCoGe
T. Hattori, Y. Ihara, Y. Nakai, K. Ishida, Y. Tada et al.
From detailed angle-resolved NMR and Meissner measurements on a ferromagnetic (FM) superconductor UCoGe (T~2.5 K and T~0.6 K), we show that superconductivity in UCoGe is tightly coupled with longitudinal FM spin fluctuations along the c axis. We found that magnetic fields along the c axis (H||c) s ... [Phys. Rev. Lett. 108, 066403 ] published .
Green's function method for line defects and gapless modes in topological insulators: Beyond the semiclassical approach
Ken Shiozaki and Satoshi Fujimoto
Defects that appear in heterostructure junctions involving topological insulators are sources of gapless modes governing the low-energy properties of the systems, as recently elucidated by Teo and Kane [Phys. Rev. B 82, 115120 (2010)]. A standard approach for the calculation of topological invariant ... [Phys. Rev. B 85, 085409 ] published .
Giant negative magnetoresistance in high-mobility two-dimensional electron systems
A. T. Hatke, M. A. Zudov, J. L. Reno, L. N. Pfeiffer, and K. W. West
We report on a giant negative magnetoresistance in very high mobility GaAs/AlGaAs heterostructures and quantum wells. The effect is the strongest at B~=1 kG, where the magnetoresistivity develops a minimum emerging at T<~2 K. Unlike the zero-field resistivity which saturates at T~=2 K, the resistivi ... [Phys. Rev. B 85, 081304 ] published .
Higher-order contributions to the Rashba-Bychkov effect with application to the Bi/Ag(111) surface alloy
Sz. Vajna, E. Simon, A. Szilva, K. Palotas, B. Ujfalussy et al.
In order to explain the anisotropic Rashba-Bychkov effect observed in several metallic-surface-state systems, we use kp perturbation theory with a simple group-theoretical analysis and construct effective Rashba Hamiltonians for different point groups up to third order in the wave number. We perform ... [Phys. Rev. B 85, 075404 ] published .
Time-dependent transport of electrons through a photon cavity
Vidar Gudmundsson, Olafur Jonasson, Chi-Shung Tang, Hsi-Sheng Goan, and Andrei Manolescu
We use a non-Markovian master equation to describe the transport of Coulomb-interacting electrons through an electromagnetic cavity with one quantized photon mode. The central system is a finite-parabolic quantum wire that is coupled weakly to external parabolic quasi-one-dimensional leads at t=0. W ... [Phys. Rev. B 85, 075306 ] published .
Pronounced first-order metamagnetic transition in the paramagnetic heavy-fermion system CeTiGe
M. Deppe, S. Lausberg, F. Weickert, M. Brando, Y. Skourski et al.
We report on the observation of large, steplike anomalies in the magnetization (DeltaM=0.74 [mu]/Ce), in the magnetostriction (Deltal/l=2.0 x 10), and in the magnetoresistance in polycrystals of the paramagnetic heavy-fermion system CeTiGe at a critical magnetic field [mu]H[approximate]12 T at low ... [Phys. Rev. B 85, 060401 ] published .
Erratum: Electrical current driven by a coherent spin wave in a bulk ferromagnetic semiconductor [Phys. Rev. B 84, 012402 (2011)]
A. A. Fraerman, K. R. Muhamatchin, and I. D. Tokman
Abstract not available. [Phys. Rev. B 85, 059901 ] published .