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# Recent Articles in Phys. Rev. B

## Recent articles in Physical Review B

Published: 2016-10-26T17:07:39-04:00

Time reversal of a wave packet with temporal modulation of gauge potential

2016-10-26T10:00:00-04:00

Author(s): Luqi Yuan, Meng Xiao, and Shanhui Fan
We show that time reversal can be achieved with a spatially uniform temporal modulation of the gauge potential. The method can be applied to the quantum wave function of electrons where there are natural gauge potentials, and to classical waves such as the acoustic and optical waves where effective …
[Phys. Rev. B 94, 140303(R)] Published Wed Oct 26, 2016

Charge and spin diffusion on the metallic side of the metal-insulator transition: A self-consistent approach

2016-10-26T10:00:00-04:00

Author(s): Thomas Wellens and Rodolfo A. Jalabert
We develop a self-consistent theory describing the spin and spatial electron diffusion in the impurity band of doped semiconductors under the effect of a weak spin-orbit coupling. The resulting low-temperature spin-relaxation time and diffusion coefficient are calculated within different schemes of …
[Phys. Rev. B 94, 144209] Published Wed Oct 26, 2016

Theoretical study of stimulated and spontaneous Hawking effects from an acoustic black hole in a hydrodynamically flowing fluid of light

2016-10-26T10:00:00-04:00

Author(s): Pjotrs Grišins, Hai Son Nguyen, Jacqueline Bloch, Alberto Amo, and Iacopo Carusotto

Given the extreme faintness of Hawking radiation from astrophysical black holes, researchers are actively pursuing the experimental quest of its analogs in condensed-matter and optical systems. This work reports a detailed theoretical study of different aspects of analog Hawking physics in a flowing fluid of exciton-polaritons in a semiconductor microcavity. Previous experimental work has demonstrated the relative ease to generate a black-hole horizon for collective sound waves in this system. Here, the authors propose realistic schemes to experimentally observe stimulated and spontaneous Hawking radiation effects, and they characterize their efficiency in view of forthcoming experiments. In particular, the study illustrates how complex shapes of the effective analog metric are naturally realized in this system and how this results in peculiar new features in the Hawking emission. The study also pinpoints the potential of quantum fluids of light for future studies and highlights the novelties and the experimental advantages of using driven-dissipative systems over conservative ultracold atomic gases.

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[Phys. Rev. B 94, 144518] Published Wed Oct 26, 2016

Fluence-dependent femtosecond quasiparticle and Eu^{2+} spin relaxation dynamics in EuFe_{2} (As,P)_{2}

2016-10-26T10:00:00-04:00

Author(s): A. Pogrebna, T. Mertelj, G. Cao, Z. A. Xu, and D. Mihailovic
We investigated temperature- and fluence-dependent dynamics of the time-resolved optical reflectivity in undoped spin-density-wave (SDW) and doped superconducting (SC) EuFe_{2}(As,P)_{2} with emphasis on the ordered Eu^{2+} spin temperature region. The data indicate that in EuFe_{2}(As,P)_{2} the SD…
[Phys. Rev. B 94, 144519] Published Wed Oct 26, 2016

Local thickness-dependent permittivity model for nonlocal bounded wire-medium structures

2016-10-26T10:00:00-04:00

Author(s): Alexander B. Yakovlev, Maziar Hedayati, Mário G. Silveirinha, and George W. Hanson
A local thickness-dependent permittivity is derived in closed form for bounded nonlocal wire-medium structures. The model takes into account spatial dispersion (as an average per length of the wires) and the effect of the boundary, and shows that an effective local model of a nonlocal medium is thic…
[Phys. Rev. B 94, 155442] Published Wed Oct 26, 2016

Publisher's Note: Temperature- and doping-dependent optical absorption in the small-polaron system Pr_{1−x} Ca_{x} MnO_{3} [Phys. Rev. B 92, 035145 (2015)]

2016-10-26T10:00:00-04:00

Author(s): S. Mildner, J. Hoffmann, P. E. Blöchl, S. Techert, and C. Jooss

[Phys. Rev. B 94, 159902] Published Wed Oct 26, 2016

Accurate ab initio tight-binding Hamiltonians: Effective tools for electronic transport and optical spectroscopy from first principles

2016-10-26T10:00:00-04:00

Author(s): Pino D'Amico, Luis Agapito, Alessandra Catellani, Alice Ruini, Stefano Curtarolo, Marco Fornari, Marco Buongiorno Nardelli, and Arrigo Calzolari
The calculations of electronic transport coefficients and optical properties require a very dense interpolation of the electronic band structure in reciprocal space that is computationally expensive and may have issues with band crossing and degeneracies. Capitalizing on a recently developed pseudoa…
[Phys. Rev. B 94, 165166] Published Wed Oct 26, 2016

Entanglement spectrum of Su-Schrieffer-Heeger-Hubbard model

2016-10-26T10:00:00-04:00

Author(s): Bing-Tian Ye, Liang-Zhu Mu, and Heng Fan
We investigate the entanglement spectrum of the ground state of the Su-Schrieffer-Heeger-Hubbard model. The topological phases of the model can be identified by degeneracy of the largest eigenvalues of entanglement spectrum. The study of the periodic boundary condition is enough to obtain the phase …
[Phys. Rev. B 94, 165167] Published Wed Oct 26, 2016

Band narrowing and Mott localization in isotropically superstrained graphene

2016-10-26T10:00:00-04:00

Author(s): L. Craco, S. S. Carara, and S. Leoni
We explore the effect of multiorbital electron-electron interactions in a two-dimensional monolayer made of elemental carbon. Using density functional dynamical mean-field theory (DFDMFT), we show that the interplay between one-particle band narrowing and sizable on-site interactions naturally stabi…
[Phys. Rev. B 94, 165168] Published Wed Oct 26, 2016

Topological insulator on honeycomb lattices and ribbons without inversion symmetry

2016-10-26T10:00:00-04:00

Author(s): Robert Triebl and Markus Aichhorn
We study the Kane-Mele-Hubbard model with an additional inversion-symmetry-breaking term. Using the topological Hamiltonian approach, we calculate the Z_{2} invariant of the system as function of spin-orbit coupling, Hubbard interaction U, and inversion-symmetry-breaking onsite potential. The phase …
[Phys. Rev. B 94, 165169] Published Wed Oct 26, 2016

Trail-Needs pseudopotentials in quantum Monte Carlo calculations with plane-wave/blip basis sets

2016-10-26T10:00:00-04:00

Author(s): N. D. Drummond, J. R. Trail, and R. J. Needs
We report a systematic analysis of the performance of a widely used set of Dirac-Fock pseudopotentials for quantum Monte Carlo (QMC) calculations. We study each atom in the periodic table from hydrogen (Z=1) to mercury (Z=80), with the exception of the 4f elements (57≤Z≤70). We demonstrate that ghos…
[Phys. Rev. B 94, 165170] Published Wed Oct 26, 2016

Phonon-dressed two-dimensional carriers on the ZnO surface

2016-10-26T10:00:00-04:00

Author(s): R. Yukawa, K. Ozawa, S. Yamamoto, H. Iwasawa, K. Shimada, E. F. Schwier, K. Yoshimatsu, H. Kumigashira, H. Namatame, M. Taniguchi, and I. Matsuda
Two-dimensional (2D) metallic states formed on the ZnO(101[over ¯]0) surface by hydrogen adsorption have been investigated using angle-resolved photoelectron spectroscopy (ARPES). The observed metallic state is characterized by a peak-dip-hump structure at just below the Fermi level and a long tail …
[Phys. Rev. B 94, 165313] Published Wed Oct 26, 2016

Resonant bonding driven giant phonon anharmonicity and low thermal conductivity of phosphorene

2016-10-26T10:00:00-04:00

Author(s): Guangzhao Qin, Xiaoliang Zhang, Sheng-Ying Yue, Zhenzhen Qin, Huimin Wang, Yang Han, and Ming Hu
Two-dimensional (2D) phosphorene, which possesses fascinating physical and chemical properties distinctively different from other 2D materials, calls for a fundamental understanding of thermal transport properties for its rapidly growing applications in nano- and optoelectronics and thermoelectrics.…
[Phys. Rev. B 94, 165445] Published Wed Oct 26, 2016

Ab initio study of electronic excitations and the dielectric function in molybdenum disulfide monolayer

2016-10-26T10:00:00-04:00

Author(s): Vito Despoja, Zoran Rukelj, and Leonardo Marušić
The propagator of the induced dynamically screened Coulomb interaction W^{ind}(Q,ω,z,z^{′}) is calculated for the MoS_{2} monolayer. The energy-loss rate of a point charge placed near the MoS_{2} monolayer is calculated (using the spatial resolution of the W^{ind} in the direction perpendicular to t…
[Phys. Rev. B 94, 165446] Published Wed Oct 26, 2016

Femtosecond-laser induced dynamics of CO on Ru(0001): Deep insights from a hot-electron friction model including surface motion

2016-10-26T10:00:00-04:00

Author(s): Robert Scholz, Gereon Floß, Peter Saalfrank, Gernot Füchsel, Ivor Lončarić, and J. I. Juaristi
A Langevin model accounting for all six molecular degrees of freedom is applied to femtosecond-laser induced, hot-electron driven dynamics of Ru(0001)(2×2):CO. In our molecular dynamics with electronic friction approach, a recently developed potential energy surface based on gradient-corrected densi…
[Phys. Rev. B 94, 165447] Published Wed Oct 26, 2016

Spontaneous formation and synchronization of vortex modes in optically induced traps for exciton-polariton condensates

2016-10-25T10:00:00-04:00

Author(s): Alexey V. Yulin, Anton S. Desyatnikov, and Elena A. Ostrovskaya
We study the dynamics of exciton-polariton condensates in reconfigurable potentials created by an incoherent optical pump. The mode selection in the effective optically induced trap is shown to be determined by the largest growth rates of the linear eigenmodes of the effective complex potential crea…
[Phys. Rev. B 94, 134310] Published Tue Oct 25, 2016

Short-time universal scaling and light-cone dynamics after a quench in an isolated quantum system in d spatial dimensions

2016-10-25T10:00:00-04:00

Author(s): Alessio Chiocchetta, Marco Tavora, Andrea Gambassi, and Aditi Mitra
We investigate the effects of fluctuations on the dynamics of an isolated quantum system represented by a (ϕ^{2})^{2} field theory with O(N) symmetry after a quench in d>2 spatial dimensions. A perturbative renormalization-group approach involving a dimensional expansion in ε=4−d is employed in order…
[Phys. Rev. B 94, 134311] Published Tue Oct 25, 2016

Charge transport in superionic and melted AgI under a magnetic field studied via molecular dynamics

2016-10-25T10:00:00-04:00

Author(s): Luca Gagliardi and Sara Bonella
Charge transport in AgI subject to an external magnetic field is studied via computer simulations. We demonstrate that a recently developed algorithm can effectively complement problematic experiments to detect the ionic Hall effect, and identify previously unreported effects such as ionic magnetore…
[Phys. Rev. B 94, 134426] Published Tue Oct 25, 2016

Barrier effect of grain boundaries on the avalanche propagation of polycrystalline plasticity

2016-10-25T10:00:00-04:00

Author(s): Tomoaki Niiyama and Tomotsugu Shimokawa
To investigate the barrier effect of grain boundaries on the propagation of avalanchelike plasticity at the atomic scale, we perform three-dimensional molecular dynamics simulations by using simplified polycrystal models including symmetric-tilt grain boundaries. The cutoffs of the stress-drop distr…
[Phys. Rev. B 94, 140102(R)] Published Tue Oct 25, 2016

Superconducting energy gap of 2H−NbSe_{2} in phonon spectroscopy

2016-10-25T10:00:00-04:00

Author(s): F. Weber, S. Rosenkranz, R. Heid, and A. H. Said
We present a high-energy-resolution inelastic x-ray scattering data investigation of the charge-density-wave (CDW) soft phonon mode upon entering the superconducting state in 2H−NbSe_{2}. Measurements were done close to the CDW ordering wave vector q_{CDW} at q=q_{CDW}+(0,0,l),0.15≤l≤0.5, for T=10K …
[Phys. Rev. B 94, 140504(R)] Published Tue Oct 25, 2016

Noncollinear antiferromagnetism of coupled spins and pseudospins in the double perovskite La_{2} CuIrO_{6}

2016-10-25T10:00:00-04:00

Author(s): Kaustuv Manna, R. Sarkar, S. Fuchs, Y. A. Onykiienko, A. K. Bera, G. Aslan Cansever, S. Kamusella, A. Maljuk, C. G. F. Blum, L. T. Corredor, A. U. B. Wolter, S. M. Yusuf, M. Frontzek, L. Keller, M. Iakovleva, E. Vavilova, H.-J. Grafe, V. Kataev, H.-H. Klauss, D. S. Inosov, S. Wurmehl, and B. Büchner
We report the structural, magnetic, and thermodynamic properties of the double perovskite compound La_{2}CuIrO_{6} from x-ray, neutron diffraction, neutron depolarization, dc magnetization, ac susceptibility, specific heat, muon-spin-relaxation (μSR), electron-spin-resonance (ESR) and nuclear magnet…
[Phys. Rev. B 94, 144437] Published Tue Oct 25, 2016

Order by disorder decision making via Berry flux

2016-10-25T10:00:00-04:00

Author(s): Benjamin O. Sung and Michael J. Lawler
Order by disorder is a decision making process for frustrated systems but often leads to simple answers. We study order by disorder in the kagome Kondo model known for its complexity seeking rich decision making capabilities. At half-filling and large Kondo coupling to hopping ratio J_{K}/t, the ful…
[Phys. Rev. B 94, 144438] Published Tue Oct 25, 2016

Observation of quantum Griffiths singularity and ferromagnetism at the superconducting LaAlO_{3} /SrTiO_{3} (110) interface

2016-10-25T10:00:00-04:00

Author(s): Shengchun Shen, Ying Xing, Pengjie Wang, Haiwen Liu, Hailong Fu, Yangwei Zhang, Lin He, X. C. Xie, Xi Lin, Jiacai Nie, and Jian Wang
Diverse phenomena emerge at the interface between band insulators LaAlO_{3} and SrTiO_{3}, such as superconductivity and ferromagnetism, showing an opportunity for potential applications as well as contributing to fundamental research interests. Here, we report the superconductor-metal transition dr…
[Phys. Rev. B 94, 144517] Published Tue Oct 25, 2016

Violation of cluster decomposition and absence of light cones in local integer and half-integer spin chains

2016-10-25T10:00:00-04:00

Author(s): L. Dell'Anna, O. Salberger, L. Barbiero, A. Trombettoni, and V. E. Korepin
We compute the ground-state correlation functions of an exactly solvable chain of integer spins, recently introduced in [R. Movassagh and P. W. Shor, arXiv:1408.1657], whose ground state can be expressed in terms of a uniform superposition of all colored Motzkin paths. Our analytical results show th…
[Phys. Rev. B 94, 155140] Published Tue Oct 25, 2016

Photoemission spectra from reduced density matrices: The band gap in strongly correlated systems

2016-10-25T10:00:00-04:00

Author(s): Stefano Di Sabatino, J. A. Berger, Lucia Reining, and Pina Romaniello
We present a method for the calculation of photoemission spectra in terms of reduced density matrices. We start from the spectral representation of the one-body Green's function G, whose imaginary part is related to photoemission spectra, and we introduce a frequency-dependent effective energy that …
[Phys. Rev. B 94, 155141] Published Tue Oct 25, 2016

Effective mass in bilayer graphene at low carrier densities: The role of potential disorder and electron-electron interaction

2016-10-25T10:00:00-04:00

Author(s): J. Li, L. Z. Tan, K. Zou, A. A. Stabile, D. J. Seiwell, K. Watanabe, T. Taniguchi, Steven G. Louie, and J. Zhu
In a two-dimensional electron gas, the electron-electron interaction generally becomes stronger at lower carrier densities and renormalizes the Fermi-liquid parameters, such as the effective mass of carriers. We combine experiment and theory to study the effective masses of electrons and holes m_{e}…
[Phys. Rev. B 94, 161406(R)] Published Tue Oct 25, 2016

Coherent control over three-dimensional spin polarization for the spin-orbit coupled surface state of Bi_{2} Se_{3}

2016-10-25T10:00:00-04:00

Author(s): Kenta Kuroda, Koichiro Yaji, M. Nakayama, A. Harasawa, Y. Ishida, S. Watanabe, C.-T. Chen, T. Kondo, F. Komori, and S. Shin
Interference of spin-up and spin-down eigenstates depicts spin rotation of electrons, which is a fundamental concept of quantum mechanics and presents technological challenges for the electrical spin manipulation. Here, we visualize this coherent spin physics through laser spin- and angle-resolved p…
[Phys. Rev. B 94, 165162] Published Tue Oct 25, 2016

Presence of exotic electronic surface states in LaBi and LaSb

2016-10-25T10:00:00-04:00

Author(s): X. H. Niu, D. F. Xu, Y. H. Bai, Q. Song, X. P. Shen, B. P. Xie, Z. Sun, Y. B. Huang, D. C. Peets, and D. L. Feng
Extremely high magnetoresistance (XMR) in the lanthanum monopnictides LaX (X=Sb,Bi) has recently attracted interest in these compounds as candidate topological materials. However, their perfect electron-hole compensation provides an alternative explanation, so the possible role of topological surfac…
[Phys. Rev. B 94, 165163] Published Tue Oct 25, 2016

Topological mirror insulators in one dimension

2016-10-25T10:00:00-04:00

Author(s): Alexander Lau, Jeroen van den Brink, and Carmine Ortix
We demonstrate the existence of topological insulators in one dimension (1D) protected by mirror and time-reversal symmetries. They are characterized by a nontrivial Z_{2} topological invariant defined in terms of the “partial” polarizations, which we show to be quantized in the presence of a 1D mir…
[Phys. Rev. B 94, 165164] Published Tue Oct 25, 2016

Revealing the role of electrons and phonons in the ultrafast recovery of charge density wave correlations in 1T−TiSe_{2}

2016-10-25T10:00:00-04:00

Author(s): C. Monney, M. Puppin, C. W. Nicholson, M. Hoesch, R. T. Chapman, E. Springate, H. Berger, A. Magrez, C. Cacho, R. Ernstorfer, and M. Wolf

Electrons in low-dimensional materials sometimes reorganize themselves with a new translational symmetry, which gives rise to an energetically more favorable ground state. This phenomenon, called a charge density wave (CDW) phase, is often the result of the coupling of electrons to phonons. In the quasi-two-dimensional material TiSe${}_{2}$, the CDW occurring at low temperature is unusual, since it appears to be driven by strong electron-hole correlations, which in turn couple to phonons. In this work, the authors use time- and angle-resolved photoemission spectroscopy to investigate the peculiar nature of the CDW phase in TiSe${}_{2}$.Depending on the temperature at which measurements are performed, they observe that the response of the material is either strongly coupled to the lattice or dominated by its electronic degrees of freedom. This selective response is enhanced by tuning the pump pulse wavelength to specific optical resonances. They conclude that their measurements do indeed confirm a combined scenario, for which both the electron-hole correlations and the coupling to phonons are essential to the origin of the CDW phase in TiSe${}_{2}$.

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[Phys. Rev. B 94, 165165] Published Tue Oct 25, 2016

Giant thermoelectric figure of merit in a noninteracting quantum dot system with massless Dirac fermions

2016-10-25T10:00:00-04:00

Author(s): Tomosuke Aono and Takashi Komine
We investigate the thermoelectric characteristics of a quantum dot system with massless Dirac fermions, in which the tunneling coupling between the quantum dot and the Dirac fermions has a pseudogap. The maximum values of the thermoelectric figure of merit and the thermopower can be made independent…
[Phys. Rev. B 94, 165311] Published Tue Oct 25, 2016

Theory of Landau level mixing in heavily graded graphene p−n junctions

2016-10-25T10:00:00-04:00

Author(s): Samuel W. LaGasse and Ji Ung Lee
We demonstrate the use of a quantum transport model to study heavily graded graphene p−n junctions in the quantum Hall regime. A combination of p−n interface roughness and delta function disorder potential allows us to compare experimental results on different devices from the literature. We find th…
[Phys. Rev. B 94, 165312] Published Tue Oct 25, 2016

Light-modulated 0-π transition in a silicene-based Josephson junction

2016-10-25T10:00:00-04:00

Author(s): Xingfei Zhou and Guojun Jin
We investigate the Andreev bound states (ABSs) and Josephson current in a silicene-based superconductor-normal-superconductor junction modulated by a perpendicular electric field and an off-resonant circularly polarized light. Based on the Dirac–Bogoliubov–de Gennes equation, we analytically derive …
[Phys. Rev. B 94, 165436] Published Tue Oct 25, 2016

Controlled formation of isolated miniband in bilayer graphene on almost commensurate sqrt[3] × sqrt[3] substrate

2016-10-25T10:00:00-04:00

Author(s): D. J. Leech and M. Mucha-Kruczyński
We investigate theoretically the interplay between the effects of a perpendicular electric field and incommensurability at the interface on the electronic properties of a heterostructure of bilayer graphene and a semiconducting substrate with a unit cell almost three times larger than that of graphe…
[Phys. Rev. B 94, 165437] Published Tue Oct 25, 2016

Determining the atomic structure of the (4×4) silicene layer on Ag(111) by combined grazing-incidence x-ray diffraction measurements and first-principles calculations

2016-10-25T10:00:00-04:00

Author(s): A. Curcella, R. Bernard, Y. Borensztein, A. Resta, M. Lazzeri, and G. Prévot
From grazing-incidence x-ray diffraction measurements and density functional theory calculations, we have precisely determined the atomic positions of the Si and Ag atoms forming the (4×4) Si/Ag(111) silicene reconstruction. A remarkable agreement is found between the experimental structure factors …
[Phys. Rev. B 94, 165438] Published Tue Oct 25, 2016

Nonreciprocal diffraction of light based on double-transition-assisted photonic Aharonov-Bohm effect

2016-10-25T10:00:00-04:00

Author(s): Fan Yang and Yanfeng Li
We propose a nonreciprocal diffraction system based on the photonic Aharonov-Bohm effect. The implementation utilizes the simultaneous up and down photonic transition of Bloch modes in a dielectric grating created by time-harmonic dielectric constant modulation. This double transition process genera…
[Phys. Rev. B 94, 165439] Published Tue Oct 25, 2016

Resolving phase information of the optical local density of state with scattering near-field probes

2016-10-25T10:00:00-04:00

Author(s): R. Prasad and R. Vincent
We theoretically discuss the link between the phase measured using a scattering optical scanning near-field microscopy (s-SNOM) and the local density of optical states (LDOS). A remarkable result is that the LDOS information is directly included in the phase of the probe. Therefore by monitoring the…
[Phys. Rev. B 94, 165440] Published Tue Oct 25, 2016

Spin-filtered and spatially distinguishable crossed Andreev reflection in a silicene-superconductor junction

2016-10-25T10:00:00-04:00

Author(s): Kangkang Li and Yan-Yang Zhang
We theoretically investigate the quantum transport in a junction between a superconductor and a silicene nanoribbon, under the effect of a magnetic exchange field. We find that for a narrow nanoribbon of silicene, remarkable crossed Andreev reflection (with a fraction >50%) can be induced in the ener…
[Phys. Rev. B 94, 165441] Published Tue Oct 25, 2016

Ultrafast carrier dynamics, band-gap renormalization, and optical properties of ZnSe nanowires

2016-10-25T10:00:00-04:00

Author(s): Lin Tian (田琳), Lorenzo di Mario, Valentina Zannier, Daniele Catone, Stefano Colonna, Patrick O’Keeffe, Stefano Turchini, Nicola Zema, Silvia Rubini, and Faustino Martelli
In this paper, we present a comprehensive study of the carrier dynamics and optical properties of ZnSe nanowires (NWs). The transparency of the sample, obtained by the growth of the ZnSe NWs on glass, allowed us to perform transmittance, reflectance, photoluminescence (PL), time-resolved PL, and pum…
[Phys. Rev. B 94, 165442] Published Tue Oct 25, 2016

Chiral interface states in graphene p−n junctions

2016-10-25T10:00:00-04:00

Author(s): Laura Cohnitz, Alessandro De Martino, Wolfgang Häusler, and Reinhold Egger
We present a theoretical analysis of unidirectional interface states which form near p−n junctions in a graphene monolayer subject to a homogeneous magnetic field. The semiclassical limit of these states corresponds to trajectories propagating along the p−n interface by a combined skipping-snaking m…
[Phys. Rev. B 94, 165443] Published Tue Oct 25, 2016

Controlling magnetic interfaces using ordered surface alloys

2016-10-24T10:00:00-04:00

Author(s): Chenlu Ji, Zhe Wang, Qiang Wu, Li Huang, and M. S. Altman
We have investigated the growth and magnetic properties of Fe thin films on the clean W(100) surface and W(100)-M c(2 × 2) (M=Cu, Ag, Au) surface alloy substrates. The influence of the interface on magnetism is assessed experimentally by studying sensitive threshold behavior in magnetic ordering usi…
[Phys. Rev. B 94, 134425] Published Mon Oct 24, 2016

Pinched hysteresis loop in defect-free ferroelectric materials

2016-10-24T10:00:00-04:00

Author(s): Bin Xu, Charles Paillard, Brahim Dkhil, and L. Bellaiche
In addition to the single polarization-versus-electric field hysteresis loop that is characteristic of ferroelectrics and the double hysteresis loop that is known to occur in antiferroelectrics, a third kind of polarization-versus-electric field function has been reported in several systems. This th…
[Phys. Rev. B 94, 140101(R)] Published Mon Oct 24, 2016

Origin of fieldlike spin-orbit torques in heavy metal/ferromagnet/oxide thin film heterostructures

2016-10-24T10:00:00-04:00

Author(s): Yongxi Ou, Chi-Feng Pai, Shengjie Shi, D. C. Ralph, and R. A. Buhrman
We report measurements of the thickness and temperature (T) dependencies of current-induced spin-orbit torques, especially the fieldlike (FL) component, in various heavy metal (HM)/normal metal (NM) spacer/ferromagnet (FM)/oxide (MgO and HfO_{x}/MgO) heterostructures. The FL torque in these samples …
[Phys. Rev. B 94, 140414(R)] Published Mon Oct 24, 2016

Elastically mediated interactions between grain boundaries and precipitates in two-phase coherent solids

2016-10-24T10:00:00-04:00

Author(s): Ye-Chuan Xu, Pierre-Antoine Geslin, and Alain Karma
We investigate analytically and numerically the interaction between grain boundaries and second phase precipitates in two-phase coherent solids in the presence of misfit strain. Our numerical study uses amplitude equations that describe the interaction of composition and stress [R. Spatschek and A. …
[Phys. Rev. B 94, 144106] Published Mon Oct 24, 2016

Relaxation time spectrum of low-energy excitations in one- and two-dimensional materials with charge or spin density waves

2016-10-24T10:00:00-04:00

Author(s): S. Sahling, G. Remenyi, J. E. Lorenzo, P. Monceau, V. L. Katkov, and V. A. Osipov
The long-time thermal relaxation of (TMTTF)_{2}Br,Sr_{14}Cu_{24}O_{41} and Sr_{2}Ca_{12}Cu_{24}O_{41} single crystals at temperatures below 1 K and magnetic field up to 10 T is investigated. The data allow us to determine the relaxation-time spectrum of the low-energy excitations caused by the charg…
[Phys. Rev. B 94, 144107] Published Mon Oct 24, 2016

Explicit construction of local conserved operators in disordered many-body systems

2016-10-24T10:00:00-04:00

Author(s): T. E. O'Brien, Dmitry A. Abanin, Guifre Vidal, and Z. Papić
The presence and character of local integrals of motion—quasilocal operators that commute with the Hamiltonian—encode valuable information about the dynamics of a quantum system. In particular, strongly disordered many-body systems can generically avoid thermalization when there are extensively many…
[Phys. Rev. B 94, 144208] Published Mon Oct 24, 2016

Relation of vibrational excitations and thermal conductivity to elastic heterogeneities in disordered solids

2016-10-24T10:00:00-04:00

Author(s): Hideyuki Mizuno, Stefano Mossa, and Jean-Louis Barrat
In crystals, molecules thermally vibrate around the periodic lattice sites. Vibrational motions are well understood in terms of phonons, which carry heat and control heat transport. The situation is notably different in disordered solids, where vibrational excitations are not phonons and can be even…
[Phys. Rev. B 94, 144303] Published Mon Oct 24, 2016

Ab initio investigation of the anomalous phonon softening in FeSi

2016-10-24T10:00:00-04:00

Author(s): Robin Stern and Georg K. H. Madsen
The anomalous softening of the acoustic phonon peak in FeSi has recently received considerable experimental attention. In our work, we investigate the effect of thermal disorder on the lattice dynamics and the filling of the narrow band gap of FeSi using density functional theory. We show, by compar…
[Phys. Rev. B 94, 144304] Published Mon Oct 24, 2016

Vorticity in electron beams: Definition, properties, and its relationship with magnetism

2016-10-24T10:00:00-04:00

Author(s): Ján Rusz, Juan-Carlos Idrobo, and Linus Wrang
Vorticity is a concept well established in fluid dynamics to describe the local tendency of a fluid to rotate. Here, we explore the vorticity of electron waves and show that it can be used to qualitatively estimate the strength of an electron magnetic circular dichroism (EMCD) signal, without resort…
[Phys. Rev. B 94, 144430] Published Mon Oct 24, 2016

Magnetism in Pd: Magnetoconductance and transport spectroscopy of atomic contacts

2016-10-24T10:00:00-04:00

Author(s): F. Strigl, M. Keller, D. Weber, T. Pietsch, and E. Scheer
Since the rapid technological progress demands for ever smaller storage units, the emergence of stable magnetic order in nanomaterials down to the single-atom regime has attracted huge scientific attention to date. Electronic transport spectroscopy has been proven to be a versatile tool for the inve…
[Phys. Rev. B 94, 144431] Published Mon Oct 24, 2016

Laser-induced torques in metallic ferromagnets

2016-10-24T10:00:00-04:00

Author(s): Frank Freimuth, Stefan Blügel, and Yuriy Mokrousov
We study laser-induced torques in bcc Fe, hcp Co, and L1_{0} FePt based on first-principles electronic structure calculations and the Keldysh nonequilibrium formalism. We find that the torques have two contributions, one from the inverse Faraday effect (IFE) and one from the optical spin-transfer to…
[Phys. Rev. B 94, 144432] Published Mon Oct 24, 2016

Quasianalytical treatment of the spin Seebeck effect on the Na_{2} molecule

2016-10-24T10:00:00-04:00

Author(s): G. Lefkidis and S. A. Reyes
We present a method to calculate from first principles the spin Seebeck effect on finite systems. Our method, which is suited for all ab initio, quantum-chemistry-based results, is demonstrated quasianalytically on the Na_{2} dimer. To this end we start from the analytical solutions of the many-body…
[Phys. Rev. B 94, 144433] Published Mon Oct 24, 2016

Physical properties of single crystalline RMg_{2} Cu_{9} (R=Y,Ce−Nd,Gd−Dy,Yb) and the search for in-plane magnetic anisotropy in hexagonal systems

2016-10-24T10:00:00-04:00

Author(s): Tai Kong, William R. Meier, Qisheng Lin, Scott M. Saunders, Sergey L. Bud'ko, Rebecca Flint, and Paul C. Canfield
Single crystals of RMg_{2}Cu_{9} (R=Y, Ce-Nd, Gd-Dy, Yb) were grown using a high-temperature solution growth technique and were characterized by measurements of room-temperature x-ray diffraction, temperature-dependent specific heat, and temperature- and field-dependent resistivity and anisotropic m…
[Phys. Rev. B 94, 144434] Published Mon Oct 24, 2016

Ultrafast cooling and heating scenarios for the laser-induced phase transition in CuO

2016-10-24T10:00:00-04:00

Author(s): Johan Hellsvik, Johan H. Mentink, and José Lorenzana
The multiferroic compound CuO exhibits low-temperature magnetic properties similar to antiferromagnetic iron oxides, while the electronic properties have much more in common with the high-T_{c} cuprate superconductors. This suggests novel possibilities for the ultrafast optical excitation of magneti…
[Phys. Rev. B 94, 144435] Published Mon Oct 24, 2016

Magnetocrystalline anisotropy of FePt: A detailed view

2016-10-24T10:00:00-04:00

Author(s): Saleem Ayaz Khan, Peter Blaha, Hubert Ebert, Jan Minár, and Ondřej Šipr
To get a reliable ab initio value for the magnetocrystalline anisotropy (MCA) energy of FePt, we employ the full-potential linearized augmented plane wave (FLAPW) method and the full-potential Korringa-Kohn-Rostoker (KKR) Green function method. The MCA energies calculated by both methods are in good…
[Phys. Rev. B 94, 144436] Published Mon Oct 24, 2016

Bose-Hubbard model on a triangular lattice with diamond ring exchange

2016-10-24T10:00:00-04:00

Author(s): V. G. Rousseau, K. Hettiarachchilage, K.-M. Tam, M. Jarrell, and J. Moreno
Ring-exchange interactions have been proposed as a possible mechanism for a Bose-liquid phase at zero temperature, a phase that is compressible with no superfluidity. Using the stochastic Green function algorithm (SGF), we study the effect of these interactions for bosons on a two-dimensional triang…
[Phys. Rev. B 94, 144514] Published Mon Oct 24, 2016

Complex superconductivity in the noncentrosymmetric compound Re_{6} Zr

2016-10-24T10:00:00-04:00

Author(s): Mojammel A. Khan, A. B. Karki, T. Samanta, D. Browne, S. Stadler, I. Vekhter, Abhishek Pandey, P. W. Adams, D. P. Young, S. Teknowijoyo, K. Cho, R. Prozorov, and D. E. Graf
We report the electronic structure, synthesis, and measurements of the magnetic, transport, and thermal properties of the polycrystalline noncentrosymmetric compound Re_{6}Zr. We observed a bulk superconducting transition at temperature T_{c}∼6.7 K, and measured the resistivity, heat capacity, therm…
[Phys. Rev. B 94, 144515] Published Mon Oct 24, 2016

High-pressure study of the basal-plane anisotropy of the upper critical field of the topological superconductor Sr_{x} Bi_{2} Se_{3}

2016-10-24T10:00:00-04:00

Author(s): A. M. Nikitin, Y. Pan, Y. K. Huang, T. Naka, and A. de Visser
We report a high-pressure transport study of the upper-critical field B_{c2}(T) of the topological superconductor Sr_{0.15}Bi_{2}Se_{3} (T_{c}=3.0 K). B_{c2}(T) was measured for magnetic fields directed along two orthogonal directions, a and a^{*}, in the trigonal basal plane. While superconductivit…
[Phys. Rev. B 94, 144516] Published Mon Oct 24, 2016

Microscopic theory of Dzyaloshinsky-Moriya interaction in pyrochlore oxides with spin-orbit coupling

2016-10-24T10:00:00-04:00

Author(s): Naoya Arakawa
Pyrochlore oxides show several fascinating phenomena, such as the formation of heavy fermions and the thermal Hall effect. Although a key to understanding some phenomena may be the Dzyaloshinsky-Moriya (DM) interaction, its microscopic origin is unclear. To clarify the microscopic origin, we constru…
[Phys. Rev. B 94, 155139] Published Mon Oct 24, 2016

Reconstruction of the phonon relaxation times using solutions of the Boltzmann transport equation

2016-10-24T10:00:00-04:00

Author(s): Mojtaba Forghani, Nicolas G. Hadjiconstantinou, and Jean-Philippe M. Péraud
We present a method for reconstructing the phonon relaxation time distribution τ_{ω}=τ(ω) (including polarization) in a material from thermal spectroscopy data. The distinguishing feature of this approach is that it does not make use of the effective thermal conductivity concept and associated appro…
[Phys. Rev. B 94, 155439] Published Mon Oct 24, 2016

Elastic versus inelastic spin-polarized electron scattering from a ferromagnetic surface

2016-10-24T10:00:00-04:00

Author(s): Sergey N. Samarin, Oleg M. Artamonov, Alexander P. Baraban, Mikhail Kostylev, Paul Guagliardo, Jamal Berakdar, and James F. Williams
Spin-polarized electron energy loss spectroscopy was applied to study the intensity asymmetry upon the reversal of the incident spin polarization of elastically and inelastically scattered polarized electrons from an epitaxial ferromagnetic Fe layer on W(110). The polarization of the incident beam w…
[Phys. Rev. B 94, 155440] Published Mon Oct 24, 2016

Theory of proximity-induced exchange coupling in graphene on hBN/(Co, Ni)

2016-10-24T10:00:00-04:00

Author(s): Klaus Zollner, Martin Gmitra, Tobias Frank, and Jaroslav Fabian
Graphene, being essentially a surface, can borrow some properties of an insulating substrate (such as exchange or spin-orbit couplings) while still preserving a great degree of autonomy of its electronic structure. Such derived properties are commonly labeled as proximity. Here we perform systematic…
[Phys. Rev. B 94, 155441] Published Mon Oct 24, 2016

Pressure-induced phase transition in LaCo_{5} studied by x-ray emission spectroscopy, x-ray diffraction, and density functional theory

2016-10-24T10:00:00-04:00

Author(s): Hitoshi Yamaoka, Yoshiya Yamamoto, Eike F. Schwier, Naohito Tsujii, Masahiro Yoshida, Yu Ohta, Hiroya Sakurai, Jung-Fu Lin, Nozomu Hiraoka, Hirofumi Ishii, Ku-Ding Tsuei, Masashi Arita, Kenya Shimada, and Jun'ichiro Mizuki
The pressure dependences of the electronic and crystal structures of LaCo_{5} have been studied with high-resolution x-ray absorption spectroscopy (XAS) and x-ray diffraction comprehensively. The lattice constant ratio of a/c shows an anomaly around 12–18 GPa without change in the lattice symmetry. …
[Phys. Rev. B 94, 165156] Published Mon Oct 24, 2016

Stripe order of La_{1.64} Eu_{0.2} Sr_{0.16} CuO_{4} in magnetic fields studied by resonant soft x-ray scattering

2016-10-24T10:00:00-04:00

Author(s): M. Zwiebler, E. Schierle, E. Weschke, B. Büchner, A. Revcolevschi, Patrick Ribeiro, J. Geck, and J. Fink
We present results on the magnetic field dependence of the stripe order in La_{1.64}Eu_{0.2}Sr_{0.16}CuO_{4} (LESCO). Using resonant soft x-ray scattering at the oxygen K edge to probe the (0.259,0,0.648) superlattice reflection, which is commonly associated to charge stripes, we found no pronounced…
[Phys. Rev. B 94, 165157] Published Mon Oct 24, 2016

Recovery of SINIS turnstile accuracy in a strongly nonequilibrium regime

2016-10-24T10:00:00-04:00

Author(s): I. M. Khaymovich and D. M. Basko
We perform a theoretical study of nonequilibrium effects in charge transport through a hybrid single-electron transistor based on a small normal metal (N) island with the gate-controlled number of electrons, tunnel-coupled to voltage-biased superconducting (S) electrodes (SINIS). Focusing on the tur…
[Phys. Rev. B 94, 165158] Published Mon Oct 24, 2016

Anomalous bulk modulus in vanadate spinels

2016-10-24T10:00:00-04:00

Author(s): Z.-Y. Li, X. Li, J.-G. Cheng, L. G. Marshall, X.-Y. Li, A. M. dos Santos, W.-G. Yang, J. J. Wu, J.-F. Lin, G. Henkelman, T. Okada, Y. Uwatoko, H. B. Cao, H. D. Zhou, J. B. Goodenough, and J.-S. Zhou
All single-valent oxide spinels are insulators. The relatively small activation energy in the temperature dependence of resistivity in vanadate spinels led to the speculation that the spinels are near the crossover from localized to itinerant electronic behavior, and the crossover could be achieved …
[Phys. Rev. B 94, 165159] Published Mon Oct 24, 2016

Oxygen-modulated quantum conductance for ultrathin HfO_{2} -based memristive switching devices

2016-10-24T10:00:00-04:00

Author(s): Xiaoliang Zhong, Ivan Rungger, Peter Zapol, and Olle Heinonen
Memristive switching devices, candidates for resistive random access memory technology, have been shown to switch off through a progression of states with quantized conductance and subsequent noninteger conductance (in terms of conductance quantum G_{0}). We have performed calculations based on dens…
[Phys. Rev. B 94, 165160] Published Mon Oct 24, 2016

Magnetotransport study of Dirac fermions in YbMnBi_{2} antiferromagnet

2016-10-24T10:00:00-04:00

Author(s): Aifeng Wang (王爱峰), I. Zaliznyak, Weijun Ren (任卫军), Lijun Wu, D. Graf, V. O. Garlea, J. B. Warren, E. Bozin, Yimei Zhu, and C. Petrovic
We report quantum transport and Dirac fermions in YbMnBi_{2} single crystals. YbMnBi_{2} is a layered material with anisotropic conductivity and magnetic order below 290 K. Magnetotransport properties, nonzero Berry phase, and small cyclotron mass indicate the presence of Dirac fermions. Angular-dep…
[Phys. Rev. B 94, 165161] Published Mon Oct 24, 2016

All-optical tailoring of single-photon spectra in a quantum-dot microcavity system

2016-10-24T10:00:00-04:00

Author(s): D. Breddermann, D. Heinze, R. Binder, A. Zrenner, and S. Schumacher
Semiconductor quantum-dot cavity systems are promising sources for solid-state-based on-demand generation of single photons for quantum communication. Commonly, the spectral characteristics of the emitted single photon are fixed by system properties such as electronic transition energies and spectra…
[Phys. Rev. B 94, 165310] Published Mon Oct 24, 2016

Continuum approach for long-wavelength acoustic phonons in quasi-two-dimensional structures

2016-10-24T10:00:00-04:00

Author(s): Dan Liu, Arthur G. Every, and David Tománek
As an alternative to atomistic calculations of long-wavelength acoustic modes of atomically thin layers, which are known to converge very slowly, we propose a quantitatively predictive and physically intuitive approach based on continuum elasticity theory. We describe a layer, independent of its thi…
[Phys. Rev. B 94, 165432] Published Mon Oct 24, 2016

Comparative study of phonon spectrum and thermal expansion of graphene, silicene, germanene, and blue phosphorene

2016-10-24T10:00:00-04:00

Author(s): Xu-Jin Ge, Kai-Lun Yao, and Jing-Tao Lü
Based on first-principles calculations using density functional theory, we study the vibrational properties and thermal expansion of monoatomic two-dimensional honeycomb lattices: graphene, silicene, germanene, and blue phosphorene. We focus on the similarities and differences of their properties, a…
[Phys. Rev. B 94, 165433] Published Mon Oct 24, 2016

Nano-cross-junction effect on phonon transport in silicon nanowire cages

2016-10-24T10:00:00-04:00

Author(s): Dengke Ma (马登科), Hongru Ding (丁鸿儒), Han Meng (孟涵), Lei Feng, Yue Wu, Junichiro Shiomi, and Nuo Yang (杨诺)
Wave effects of phonons can give rise to controllability of heat conduction in nanostructures beyond that by particle scattering at surfaces and interfaces. In this paper, we propose a new class of three-dimensional nanostructures: a silicon-nanowire-cage (SiNWC) structure consisting of silicon nano…
[Phys. Rev. B 94, 165434] Published Mon Oct 24, 2016

Violation of Onsager's theorem in approximate master equation approaches

2016-10-24T10:00:00-04:00

Author(s): Kevin Marc Seja, Gediminas Kiršanskas, Carsten Timm, and Andreas Wacker
The consistency with Onsager's theorem is examined for commonly used perturbative approaches, such as the Redfield and second-order von Neumann master equations, for thermoelectric transport through nanostructures. We study a double quantum dot, which requires coherences between states for a correct…
[Phys. Rev. B 94, 165435] Published Mon Oct 24, 2016

Weak coupling of pseudoacoustic phonons and magnon dynamics in the incommensurate spin-ladder compound Sr_{14} Cu_{24} O_{41}

2016-10-21T10:00:00-04:00

Author(s): Xi Chen, Dipanshu Bansal, Sean Sullivan, Douglas L. Abernathy, Adam A. Aczel, Jianshi Zhou, Olivier Delaire, and Li ShiIncommensurate compounds consist of two or more interpenetrating sublattices with lattice periods incommensurate along one or more crystal axes. Intriguing lattice dynamics have been predicted for these compounds and are relevant to not only the thermal properties but also electronic, optical, and magnetic properties via coupling between different energy excitations. Here, the authors report inelastic neutron scattering measurements of phonon and magnon dispersions in Sr14Cu24O41, which contains incommensurate chain and ladder substructures. Two distinct acoustic phononlike modes, corresponding to the sliding motion of one sublattice against the other, are observed for atomic motions polarized along the incommensurate axis. In the long-wavelength limit, it is found that the sliding mode shows a remarkably small energy gap, indicating very weak interactions between the two incommensurate sublattices. The measurements also reveal an appreciable contribution from gapped magnons to the low-temperature specific heat, as well as a gapped and steep linear magnon dispersion of the ladders. The high group velocity of this magnon branch and weak coupling with acoustic phonons can explain the large magnon thermal conductivity in Sr14Cu24O41 crystals. These findings offer new insights into the phonon and magnon dynamics and thermal transport properties of incommensurate magnetic crystals that contain low-dimensional substructures.[Phys. Rev. B 94, 134309] Published Fri Oct 21, 2016[...]

Finding and proving the exact ground state of a generalized Ising model by convex optimization and MAX-SAT

2016-10-21T10:00:00-04:00

Author(s): Wenxuan Huang, Daniil A. Kitchaev, Stephen T. Dacek, Ziqin Rong, Alexander Urban, Shan Cao, Chuan Luo, and Gerbrand Ceder

Lattice models are widely used to represent the statistical mechanics of condensed phases for the study of alloy thermodynamics, phase transitions, magnetic properties, fluid mechanics, and other applications. A longstanding problem has been the identification of the true global ground states of a lattice model, which is challenging for general models, and only a limited number of solutions for highly simplified systems are known. Here, a practical and general algorithm is presented that allows to determine provable periodically constrained ground states of complex lattice models up to a given unit cell size and in most cases is able to prove global optimality over all possible choices of unit cells. This universal algorithm is developed by reformulating the ground-state problem in terms of maximum satisfiability (MAX-SAT) and convex optimization, which results in both provable accuracy and sufficient numerical efficiency to handle systems of physically relevant complexity. Considering that lattice-model ground states are conventionally solved using simulated annealing or genetic algorithms, techniques that are often unable to find the true global minimum and provide no handle to prove the optimality of their results, this work promises to resolve the longstanding uncertainties in lattice models of important physical phenomena.

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[Phys. Rev. B 94, 134424] Published Fri Oct 21, 2016

Nuclear magnetic relaxation rates of unconventional superconductivity in doped topological insulators

2016-10-21T10:00:00-04:00

Author(s): Yuki Nagai and Yukihiro Ota
We study the temperature dependence of nuclear magnetic relaxation (NMR) rates to detect unconventional superconductivity in doped topological insulators, such as M(=Cu,Nb,Sr)_{x}Bi_{2}Se_{3} and Sn_{1−x}In_{x}Te. The Hebel-Slichter coherence effect below a critical temperature T_{c} depends on the …
[Phys. Rev. B 94, 134516] Published Fri Oct 21, 2016

Strength coupling in mixed phases under high pressure

2016-10-21T10:00:00-04:00

Author(s): Xiaozhi Yan, Haini Dong, Guangai Sun, Xiangting Ren, Duanwei He, and Wenge Yang
The strength of a material can be altered by temperature, pressure, grain size, and orientation distributions. At the microscale, neighboring grains often play important roles in the elastic and plastic deformation process. By applying high pressure to a mixture of germanium and gold powder in the v…
[Phys. Rev. B 94, 144104] Published Fri Oct 21, 2016

Fivefold increase of hydrogen uptake in MOF74 through linker decorations

2016-10-21T10:00:00-04:00

Author(s): C. A. Arter, S. Zuluaga, D. Harrison, E. Welchman, and T. Thonhauser
We present ab initio results for linker decorations in Mg-MOF74, i.e., attaching various metals M=Li, Na, K, Sc, Cr, Mn, Fe, Ni, Cu, Zn, Rb, Pd, Ag, and Pt near the ring of the linker, creating new strong adsorption sites and thus maximizing small-molecule uptake. We find that in most cases these de…
[Phys. Rev. B 94, 144105] Published Fri Oct 21, 2016

Disentanglement of bulk and interfacial spin Hall effect in ferromagnet/normal metal interface

2016-10-21T10:00:00-04:00

Author(s): X. Zhou, M. Tang, X. L. Fan, X. P. Qiu, and S. M. Zhou
Spin Hall effect in PdPt alloys in contact with ferromagnetic Ni_{80}Fe_{20} alloys has been studied by spin torque ferromagnetic resonance technique. The spin torque spin Hall angle (ST-SHA) proves to be contributed by the interfacial and bulk SHAs. The bulk SHA is dominated by the skew scattering …
[Phys. Rev. B 94, 144427] Published Fri Oct 21, 2016

Coarsening dynamics of topological defects in thin permalloy films

2016-10-21T10:00:00-04:00

Author(s): Ilari Rissanen and Lasse Laurson
We study the dynamics of topological defects in the magnetic texture of rectangular permalloy thin-film elements during relaxation from random magnetization initial states. Our full micromagnetic simulations reveal complex defect dynamics during relaxation towards the stable Landau closure domain pa…
[Phys. Rev. B 94, 144428] Published Fri Oct 21, 2016

Origin of magnetic anisotropy in doped Ce_{2} Co_{17} alloys

2016-10-21T10:00:00-04:00

Author(s): Liqin Ke, D. A. Kukusta, and Duane D. Johnson
Magnetocrystalline anisotropy (MCA) in doped Ce_{2}Co_{17} and other competing structures was investigated using density functional theory. We confirmed that the MCA contribution from dumbbell Co sites is very negative. Replacing Co dumbbell atoms with a pair of Fe or Mn atoms greatly enhance the un…
[Phys. Rev. B 94, 144429] Published Fri Oct 21, 2016

Hidden sign-changing s-wave superconductivity in monolayer FeSe

2016-10-21T10:00:00-04:00

Author(s): Yi Gao, Yan Yu, Tao Zhou, Huaixiang Huang, and Qiang-Hua Wang
Combining the recent scanning tunneling microscopy (STM) and angle-resolved photoemission spectroscopy (ARPES) measurements, we construct a tight-binding model suitable for describing the band structure of monolayer FeSe grown on SrTiO_{3}. Then we propose a possible pairing function, which can well…
[Phys. Rev. B 94, 144512] Published Fri Oct 21, 2016

Combined effects of Sr substitution and pressure on the ground states in CaFe_{2} As_{2}

2016-10-21T10:00:00-04:00

Author(s): S. Knöner, E. Gati, S. Köhler, B. Wolf, U. Tutsch, S. Ran, M. S. Torikachvili, S. L. Bud'ko, P. C. Canfield, and M. Lang
We present a detailed study of the combined effects of Sr substitution and hydrostatic pressure on the ground-state properties of CaFe_{2}As_{2}. Measurements of the electrical resistance and magnetic susceptibility, both at ambient and finite pressure P≤2 GPa, were performed on Ca_{1−x}Sr_{x}Fe_{2}…
[Phys. Rev. B 94, 144513] Published Fri Oct 21, 2016

Possible Bose-Einstein condensate associated with an orbital degree of freedom in the Mott insulator CaCrO_{3}

2016-10-21T10:00:00-04:00

Author(s): J.-S. Zhou, L.-P. Cao, J. A. Alonso, J. Sanchez-Benitez, M. T. Fernandez-Diaz, X. Li, J.-G. Cheng, L. G. Marshall, C.-Q. Jin, and J. B. Goodenough
Whether CaCrO_{3} is a Mott insulator or a correlated metal is still controversial. We have performed measurements of magnetization, specific heat, and thermal conductivity on CaCrO_{3} samples selected from many batches of high-pressure synthesis. The single-crystal CaCrO_{3} sample exhibits an unp…
[Phys. Rev. B 94, 155137] Published Fri Oct 21, 2016

Orbital-dependent Fermi surface shrinking as a fingerprint of nematicity in FeSe

2016-10-21T10:00:00-04:00

Author(s): Laura Fanfarillo, Joseph Mansart, Pierre Toulemonde, Hervé Cercellier, Patrick Le Fèvre, François Bertran, Belen Valenzuela, Lara Benfatto, and Véronique Brouet
A large anisotropy in the electronic properties across a structural transition in several correlated systems has been identified as the key manifestation of electronic nematic order, breaking rotational symmetry. In this context, FeSe is attracting tremendous interest, since electronic nematicity de…
[Phys. Rev. B 94, 155138] Published Fri Oct 21, 2016

Observation of the exciton Mott transition in the photoluminescence of coupled quantum wells

2016-10-21T10:00:00-04:00

Author(s): Gabija Kiršanskė, Petru Tighineanu, Raphaël S. Daveau, Javier Miguel-Sánchez, Peter Lodahl, and Søren Stobbe
Indirect excitons in coupled quantum wells have long radiative lifetimes and form a cold quasi-two-dimensional population suitable for studying collective quantum effects. Here we report the observation of the exciton Mott transition from an insulating (excitons) to a conducting (ionized electron-ho…
[Phys. Rev. B 94, 155438] Published Fri Oct 21, 2016

Compass impurity model of Tb substitution in Sr_{2} IrO_{4}

2016-10-21T10:00:00-04:00

Author(s): Long Zhang, Fa Wang, and Dung-Hai Lee
We show that upon Tb substitution the interaction between the magnetic moments on the impurity Tb^{4+} ion and its surrounding Ir^{4+} ions is described by a “compass” model, i.e., an Ising-like interaction favoring the magnetic moments across each bond to align along the bond direction. Such an int…
[Phys. Rev. B 94, 161118(R)] Published Fri Oct 21, 2016

Measurement of collective excitations in VO_{2} by resonant inelastic x-ray scattering

2016-10-21T10:00:00-04:00

Author(s): Haowei He, A. X. Gray, P. Granitzka, J. W. Jeong, N. P. Aetukuri, R. Kukreja, Lin Miao, S. Alexander Breitweiser, Jinpeng Wu, Y. B. Huang, P. Olalde-Velasco, J. Pelliciari, W. F. Schlotter, E. Arenholz, T. Schmitt, M. G. Samant, S. S. P. Parkin, H. A. Dürr, and L. Andrew Wray
Vanadium dioxide is of broad interest as a spin-1/2 electron system that realizes a metal-insulator transition near room temperature, due to a combination of strongly correlated and itinerant electron physics. Here, resonant inelastic x-ray scattering is used to measure the excitation spectrum of ch…
[Phys. Rev. B 94, 161119(R)] Published Fri Oct 21, 2016

Effective Hamiltonian based Monte Carlo for the BCS to BEC crossover in the attractive Hubbard model

2016-10-21T10:00:00-04:00

Author(s): Kanika Pasrija, Prabuddha B. Chakraborty, and Sanjeev Kumar
We present an effective Hamiltonian based real-space approach for studying the weak-coupling BCS to the strong-coupling Bose-Einstein condensate crossover in the two-dimensional attractive Hubbard model at finite temperatures. We introduce and justify an effective classical Hamiltonian to describe t…
[Phys. Rev. B 94, 165150] Published Fri Oct 21, 2016

Improved pseudopotential transferability for magnetic and electronic properties of binary manganese oxides from DFT+U+J calculations

2016-10-21T10:00:00-04:00

Author(s): Jin Soo Lim, Diomedes Saldana-Greco, and Andrew M. Rappe
We employ the fully anisotropic DFT+U+J approach with the PBEsol functional to investigate ground-state magnetic and electronic properties of bulk binary manganese oxides: MnO, Mn_{3}O_{4}, α−Mn_{2}O_{3}, and β−MnO_{2}, in order of increasing Mn valence. The computed crystal structures, noncollinear…
[Phys. Rev. B 94, 165151] Published Fri Oct 21, 2016

Time-resolved dynamical Franz-Keldysh effect produced by an elliptically polarized laser

2016-10-21T10:00:00-04:00

Author(s): T. Otobe
An analytical formula is reported describing the time-resolved dynamical Franz-Keldysh effect (Tr-DFKE) produced by an elliptically polarized laser at subfemtosecond timescale. The Houston function is assumed as the time-dependent wave function of the parabolic two-band system. For elliptical polari…
[Phys. Rev. B 94, 165152] Published Fri Oct 21, 2016

Antiferroquadrupolar correlations in the quantum spin ice candidate Pr_{2} Zr_{2} O_{7}

2016-10-21T10:00:00-04:00

Author(s): S. Petit, E. Lhotel, S. Guitteny, O. Florea, J. Robert, P. Bonville, I. Mirebeau, J. Ollivier, H. Mutka, E. Ressouche, C. Decorse, M. Ciomaga Hatnean, and G. Balakrishnan
We present an experimental study of the quantum spin ice candidate pyrochlore compound Pr_{2}Zr_{2}O_{7} by means of magnetization measurements, specific heat, and neutron scattering up to 12 T and down to 60 mK. When the field is applied along the [111] and [11[over ¯]0] directions, k=0 field-induc…
[Phys. Rev. B 94, 165153] Published Fri Oct 21, 2016

Anomalous three-dimensional bulk ac conduction within the Kondo gap of SmB_{6} single crystals

2016-10-21T10:00:00-04:00

Author(s): N. J. Laurita, C. M. Morris, S. M. Koohpayeh, P. F. S. Rosa, W. A. Phelan, Z. Fisk, T. M. McQueen, and N. P. ArmitageThe Kondo insulator SmB_{6} has long been known to display anomalous transport behavior at low temperatures, T <5 K. In this temperatures range, a plateau is observed in the dc resistivity, contrary to the exponential divergence expected for a gapped system. Recent theoretical calculations suggest that SmB_{6} may be the first topological Kondo insulator (TKI) and propose that the residual conductivity is due to topological surface states which reside within the Kondo gap. Since the TKI prediction many experiments have claimed to observe high mobility surface states within a perfectly insulating hybridization gap. Here, we investigate the low energy optical conductivity within the hybridization gap of single crystals of SmB_{6} via time domain terahertz spectroscopy. Samples grown by both optical floating zone and aluminum flux methods are investigated to probe for differences originating from sample growth techniques. We find that both samples display significant three-dimensional bulk conduction originating within the Kondo gap. Although SmB_{6} may be a bulk dc insulator, it shows significant bulk ac conduction that is many orders of magnitude larger than any known impurity band conduction. The nature of these in-gap states and their coupling with the low energy spin excitons of SmB_{6} is discussed. Additionally, the well-defined conduction path geometry of our optical experiments allows us to show that any surface states, [...]

Kernel-corrected random-phase approximation for the uniform electron gas and jellium surface energy

2016-10-21T10:00:00-04:00

Author(s): Adrienn Ruzsinszky, Lucian A. Constantin, and J. M. Pitarke
We introduce and test a nonlocal energy-optimized model kernel (NEO) within the adiabatic connection fluctuation-dissipation (ACFD) density-functional theory for the jellium surface and uniform electron gas, as benchmarks for simple metallic systems. Our model kernel is short ranged for the uniform …
[Phys. Rev. B 94, 165155] Published Fri Oct 21, 2016

Theory of substrate-directed heat dissipation for single-layer graphene and other two-dimensional crystals

2016-10-21T10:00:00-04:00

Author(s): Zhun-Yong Ong, Yongqing Cai, and Gang Zhang
We present a theory of the phononic thermal (Kapitza) resistance at the interface between graphene or another single-layer two-dimensional (2D) crystal (e.g., MoS_{2}) and a flat substrate, based on a modified version of the cross-plane heat transfer model by Persson, Volokitin, and Ueba [J. Phys.: …
[Phys. Rev. B 94, 165427] Published Fri Oct 21, 2016

First-principles studies of electric field effects on the electronic structure of trilayer graphene

2016-10-21T10:00:00-04:00

Author(s): Yun-Peng Wang, Xiang-Guo Li, James N. Fry, and Hai-Ping Cheng
A gate electric field is a powerful way to manipulate the physical properties of nanojunctions made of two-dimensional crystals. To simulate field effects on the electronic structure of trilayer graphene, we used density functional theory in combination with the effective screening medium method, wh…
[Phys. Rev. B 94, 165428] Published Fri Oct 21, 2016

Hypergeometric resummation of self-consistent sunset diagrams for steady-state electron-boson quantum many-body systems out of equilibrium

2016-10-21T10:00:00-04:00

Author(s): Héctor Mera, Thomas G. Pedersen, and Branislav K. Nikolić
A newly developed hypergeometric resummation technique [H. Mera et al., Phys. Rev. Lett. 115, 143001 (2015)] provides an easy-to-use recipe to obtain conserving approximations within the self-consistent nonequilibrium many-body perturbation theory. We demonstrate the usefulness of this technique by…
[Phys. Rev. B 94, 165429] Published Fri Oct 21, 2016

Magnetic phases in periodically rippled graphene

2016-10-21T10:00:00-04:00

Author(s): M. Pilar López-Sancho and Luis Brey
We study the effects that ripples induce on the electrical and magnetic properties of graphene. The variation of the interatomic distance created by the ripples translates in a modulation of the hopping parameter between carbon atoms. A tight-binding Hamiltonian including a Hubbard interaction term …
[Phys. Rev. B 94, 165430] Published Fri Oct 21, 2016

Boundary scattering effects on magnetotransport of narrow metallic wires and films

2016-10-21T10:00:00-04:00

Author(s): E. Khalaf and P. M. Ostrovsky
Electron transport in thin metallic wires and films is strongly influenced by the quality of their surface. Weak localization and magnetoconductivity are also sensitive to the electron scattering at the edges of the sample. We study weak localization effects in a two-dimensional electron gas pattern…
[Phys. Rev. B 94, 165431] Published Fri Oct 21, 2016

Monazite-type SrCrO_{4} under compression

2016-10-20T10:00:00-04:00

Author(s): J. Gleissner, D. Errandonea, A. Segura, J. Pellicer-Porres, M. A. Hakeem, J. E. Proctor, S. V. Raju, R. S. Kumar, P. Rodríguez-Hernández, A. Muñoz, S. Lopez-Moreno, and M. Bettinelli
We report a high-pressure study of monoclinic monazite-type SrCrO_{4} up to 26 GPa. Therein we combined x-ray diffraction, Raman, and optical-absorption measurements with ab initio calculations, to find a pressure-induced structural phase transition of SrCrO_{4} near 8–9 GPa. Evidence of a second ph…
[Phys. Rev. B 94, 134108] Published Thu Oct 20, 2016