Condensed Matter

Pair density functional theory utilizing the noninteracting reference system: An effective initial theory

Masahiko Higuchi and Katsuhiko Higuchi
We present a pair density (PD) functional scheme utilizing the noninteracting reference system. In order to check to what extent this scheme can express the correlation effects, actual calculations are performed for the neutral neon atom. It is shown that this scheme reproduces about 20% of the corr ... [Phys. Rev. B 78, 125101 (2008)] published Thu Sep 4, 2008.

Magnetoconductance of rectangular arrays of quantum rings

Orsolya Kalman, Peter Foldi, Mihaly G. Benedict, and F. M. Peeters
Electron transport through multiterminal rectangular arrays of quantum rings is studied in the presence of Rashba-type spin-orbit interaction (SOI) and of a perpendicular magnetic field. Using the analytic expressions for the transmission and reflection coefficients for single rings we obtain the co ... [Phys. Rev. B 78, 125306 (2008)] published Thu Sep 4, 2008.

Controlling the fluorescence lifetime of a single emitter on the nanoscale using a plasmonic superlens

L. S. Froufe-Perez and R. Carminati
Coupling a single dipole emitter to a metallic nanoparticle through the optical modes of a planar superlens made of left-handed material can lead to substantial modifications of its spontaneous decay rate. We provide a quantitative study based on exact numerical simulation and show that such a schem ... [Phys. Rev. B 78, 125403 (2008)] published Thu Sep 4, 2008.

Evidence of the role of contacts on the observed electron-hole asymmetry in graphene

B. Huard, N. Stander, J. A. Sulpizio, and D. Goldhaber-Gordon
We perform electrical transport measurements in graphene with several sample geometries. In particular, we design invasive probes crossing the whole graphene sheet as well as external probes connected through graphene side arms. The four-probe conductance measured between external probes varies line ... [Phys. Rev. B 78, 121402 (2008)] published Thu Sep 4, 2008.

Diamagnetic persistent currents for electrons in ballistic billiards subject to a point flux

Oleksandr Zelyak and Ganpathy Murthy
We study the persistent current of noninteracting electrons subject to a pointlike magnetic flux in the simply connected chaotic Robnik-Berry quantum billiard and also in an annular analog thereof. For the simply connected billiard, we find a large diamagnetic contribution to the persistent current ... [Phys. Rev. B 78, 125305 (2008)] published Thu Sep 4, 2008.

Contribution of the electric quadrupole resonance in optical metamaterials

David J. Cho, Feng Wang, Xiang Zhang, and Y. Ron Shen
Optical metamaterials can exhibit negative index of refraction when both the effective permittivity and permeability are negative. The negative permeability is usually considered to be associated with a magnetic dipole resonance and the contribution from electric quadrupoles is neglected. Here, we s ... [Phys. Rev. B 78, 121101 (2008)] published Thu Sep 4, 2008.

Percolative spin-dependent transport in mesoscopic epitaxial Fe plaquettes of tailored connectivity

S. K. Bose, R. Sharma, and R. C. Budhani
Spin-dependent charge transport in a two-tier granular system consisting of mesoscopic Fe plaquettes over which silver nanospheres are dispersed is investigated. This system transits from a Coulomb blockade regime with a finite voltage threshold for charge flow to an infinitely connected network sho ... [Phys. Rev. B 78, 115403 (2008)] published Thu Sep 4, 2008.

Segregation of Cr impurities at bcc iron surfaces: First-principles calculations

Adam Kiejna and Elwira Wachowicz
The segregation of Cr impurities placed in different layers at four low-index iron surfaces is studied from first principles in the dilute limit of Cr concentration. The surface segregation depends strongly on the surface orientation. For a single Cr atom in the computational cell, configurations wi ... [Phys. Rev. B 78, 113403 (2008)] published Thu Sep 4, 2008.

Grand canonical Gutzwiller approximation for magnetic inhomogeneous systems

Noboru Fukushima
The Gutzwiller approximation (GA) for Gutzwiller-projected grand canonical wave functions with fugacity factors is investigated in detail. Our systems in general contain inhomogeneity and local magnetic moments. In deriving renormalization formulas, we also derive or estimate terms of higher powers ... [Phys. Rev. B 78, 115105 (2008)] published Thu Sep 4, 2008.

Near-field radiative heat transfer between a sphere and a substrate

Arvind Narayanaswamy, Sheng Shen, and Gang Chen
Near-field force and energy exchange between two objects due to quantum electrodynamic fluctuations give rise to interesting phenomena such as Casimir and van der Waals forces and thermal radiative transfer exceeding Planck's theory of blackbody radiation. Although significant progress has been made ... [Phys. Rev. B 78, 115303 (2008)] published Thu Sep 4, 2008.

Towards a theoretical description of molecular junctions in the Coulomb blockade regime based on density functional theory

R. Stadler, V. Geskin, and J. Cornil
Nonequilibrium Green's function techniques (NEGF) combined with density functional theory (DFT) calculations have become a standard tool for the description of electron transport through single molecule nanojunctions in the coherent tunneling regime. However, the applicability of these methods for t ... [Phys. Rev. B 78, 113402 (2008)] published Thu Sep 4, 2008.

Fermi liquid instabilities in two-dimensional lattice models

C. A. Lamas, D. C. Cabra, and N. Grandi
We develop a procedure for detecting Fermi liquid instabilities by extending the analysis of Pomeranchuk to two-dimensional lattice systems. The method is very general and straightforward to apply, thus, provides a powerful tool for the search of exotic phases. We test it by applying it to a lattice ... [Phys. Rev. B 78, 115104 (2008)] published Thu Sep 4, 2008.

Electronic structure of graphene and doping effect on SiO[sub 2]

Yong-Ju Kang, Joongoo Kang, and K. J. Chang
First-principles calculations show that the electronic structure of graphene on SiO strongly depends on the surface polarity and interface geometry. Surface dangling bonds mediate the coupling to graphene and can induce hole or electron doping via charge transfer even in the absence of extrinsic imp ... [Phys. Rev. B 78, 115404 (2008)] published Thu Sep 4, 2008.

Density functional study of surface-supported planar magic Ag nanoclusters

Ya-Ping Chiu, Ching-Ming Wei, and Chia-Seng Chang
Experimentally, self-organized Ag planar clusters have been observed on the periodic template found on the Pb quantum islands, which are grown on the Si(111) surface. These planar clusters register a remarkable abundance variation at some specific atomic numbers and possess enhanced stability. They ... [Phys. Rev. B 78, 115402 (2008)] published Thu Sep 4, 2008.

Low-temperature density matrix renormalization group using regulated polynomial expansion

Shigetoshi Sota and Takami Tohyama
We propose a density matrix renormalization group (DMRG) technique at finite temperatures. As is the case of the ground-state DMRG, we use a single-target state that is calculated by making use of a regulated polynomial expansion. Both static and dynamical quantities are obtained after a random-samp ... [Phys. Rev. B 78, 113101 (2008)] published Thu Sep 4, 2008.

Fast molecular-dynamics simulation for ferroelectric thin-film capacitors using a first-principles effective Hamiltonian

Takeshi Nishimatsu, Umesh V. Waghmare, Yoshiyuki Kawazoe, and David Vanderbilt
A newly developed fast molecular dynamics method is applied to BaTiO ferroelectric thin-film capacitors with short-circuited electrodes or under applied voltage. The molecular dynamics simulations based on a first-principles effective Hamiltonian clarify that dead layers (or passive layers) between ... [Phys. Rev. B 78, 104104 (2008)] published Thu Sep 4, 2008.

Dynamic origin of the morphotropic phase boundary: Soft modes and phase instability in 0.68Pb(Mg[sub 1/3]Nb[sub 2/3]O[sub 3])-0.32PbTiO[sub 3]

Hu Cao, Chris Stock, Guangyong Xu, Peter M. Gehring, Jiefang Li et al.
We report neutron inelastic scattering and high-resolution x-ray diffraction measurements on single crystal 0.68Pb(MgNbO)-0.32PbTiO (PMN-0.32PT), a relaxor ferroelectric material that lies within the compositional range of the morphotropic phase boundary (MPB) where the piezoelectric properties of P ... [Phys. Rev. B 78, 104103 (2008)] published Thu Sep 4, 2008.

Exchange interactions and critical temperature of bulk and thin films of MnSi: A density functional theory study

Mahboubeh Hortamani, Leonid Sandratskii, Peter Kratzer, Ingrid Mertig, and Matthias Scheffler
Recent theoretical work [H. Wu et al., Phys. Rev. Lett. 92, 237202 (2004); M. Hortamani et al., Phys. Rev. B 74, 205305 (2006); M. Hortamani, Ph.D. thesis, Freie Universitat, Berlin, 2006] predicted ferromagnetism at zero temperature in thin MnSi films of B2-type crystal structure on Si(100). The re ... [Phys. Rev. B 78, 104402 (2008)] published Thu Sep 4, 2008.

Fermi arc in the superconducting state of impurity-doped Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub 8]

T. Sato, K. Terashima, K. Nakayama, S. Souma, T. Takahashi et al.
We have performed ultrahigh energy- and momentum-resolved angle-resolved photoemission spectroscopy of impurity-doped BiSrCaCuO. We found that the point node of the superconducting gap near the (pi/2,pi/2) point in a pristine sample gradually evolves into a small gapless Fermi arc upon Zn or Ni dopi ... [Phys. Rev. B 78, 100502 (2008)] published Thu Sep 4, 2008.

X-ray magnetic circular dichroism in CeFe[sub 2]: First-principles calculations

V. N. Antonov, D. A. Kukusta, and A. N. Yaresko
The x-ray magnetic circular dichroism (XMCD) spectra of CeFe at the Ce L, M, Fe K, and L edges are investigated theoretically from first principles, using the fully relativistic Dirac linear muffin-tin orbital band-structure method. The electronic structure is obtained with the local spin-density ap ... [Phys. Rev. B 78, 094401 (2008)] published Thu Sep 4, 2008.

Diverging giant magnetoresistance in ferromagnet-superconductor-ferromagnet trilayers

Soumen Mandal, R. C. Budhani, Jiaqing He, and Y. Zhu
The relevance of pair-breaking by exchange and dipolar fields, and by injected spins in a low carrier density cuprate YPrBaCuO sandwiched between two ferromagnetic LaSrMnO layers is examined. At low external field (H), the system shows a giant magnetoresistance (GMR), which diverges deep in the supe ... [Phys. Rev. B 78, 094502 (2008)] published Thu Sep 4, 2008.

Publisher's Note: Monte Carlo simulations of the directional-ordering transition in the two-dimensional classical and quantum compass model [Phys. Rev. B [bold 78], 064402 (2008)]

Sandro Wenzel and Wolfhard Janke
... [Phys. Rev. B 78, 099902 (2008)] published Thu Sep 4, 2008.

Effect of grain size on the transition between ferroelectric and relaxor states in 0.8Pb(Mg[sub 1/3]Nb[sub 2/3])O[sub 3]-0.2PbTiO[sub 3] ceramics

R. Jimenez, H. Amorin, J. Ricote, J. Carreaud, J. M. Kiat et al.
The phase transition between the ferroelectric and relaxor states in 0.8Pb(MgNb)O-0.2PbTiO ceramics with decreasing grain sizes in the submicron range, down to the nanoscale, has been studied with measurements of the temperature dependence of the dielectric and elastic properties across the transiti ... [Phys. Rev. B 78, 094103 (2008)] published Thu Sep 4, 2008.

Nonlocal Landau theory of the magnetic phase diagram of highly frustrated magnetoelectric CuFeO[sub 2]

M. L. Plumer
A nonlocal Landau-type free-energy functional of the spin density is developed to model the large variety of magnetic states, which occur in the magnetic-fieldtemperature phase diagram of magnetoelectric CuFeO. Competition among long-range quadratic exchange, biquadratic antisymmetric exchange, and ... [Phys. Rev. B 78, 094402 (2008)] published Thu Sep 4, 2008.

Onset of spontaneous electrostrictive strain below 520 K in Pr-doped SrTiO[sub 3]

Rajeev Ranjan, Rohini Garg, Rudi Hackl, Anatoliy Senyshyn, Elmar Schmidbauer et al.
SrPrTiO ceramic is shown to exhibit anomalous value of cubic lattice parameter at room temperature. A combination of temperature dependent dielectric and synchrotron x-ray powder-diffraction study has revealed that the anomalous lattice parameter has contribution from spontaneous electrostrictive st ... [Phys. Rev. B 78, 092102 (2008)] published Thu Sep 4, 2008.

Magnetic oscillations of resistivity and absorption of radiation in quantum wells with two populated subbands

O. E. Raichev
The dynamic (ac) conductivity tensor of quantum wells with two populated subbands in the presence of a magnetic field perpendicular to the well layer is calculated theoretically. The microscopic theory is based on the Kubo formalism assuming a detailed consideration of elastic scattering of electron ... [Phys. Rev. B 78, 125304 (2008)] published Wed Sep 3, 2008.

Theory of the excitation of the vibrational mode of an adatom-substrate system under a resonant laser field

Jie Ma (马杰), Enge Wang (王恩哥), Zhenyu Zhang (张振宇), and Biao Wu (吴飙)
We present a theoretical description of the excitation of a stretch mode and energy transfers among different degrees of freedom within an adatom-substrate system under an infrared resonant laser field. There are two competing mechanisms via which the adatom-substrate bond can be highly excited: The ... [Phys. Rev. B 78, 125303 (2008)] published Wed Sep 3, 2008.

Room-temperature superfluidity in graphene bilayers

Hongki Min, Rafi Bistritzer, Jung-Jung Su, and A. H. MacDonald
Because graphene is an atomically two-dimensional gapless semiconductor with nearly identical conduction and valence bands, graphene-based bilayers are attractive candidates for high-temperature electron-hole pair condensation. We present estimates which suggest that the Kosterlitz-Thouless temperat ... [Phys. Rev. B 78, 121401 (2008)] published Wed Sep 3, 2008.

Effective bandstructure in the insulating phase versus strong dynamical correlations in metallic VO[sub 2]

Jan M. Tomczak, Ferdi Aryasetiawan, and Silke Biermann
Using a general analytical continuation scheme for cluster dynamical mean-field calculations, we analyze real-frequency self-energies, momentum-resolved spectral functions, and one-particle excitations of the metallic and insulating phases of VO. While for the former dynamical correlations and lifet ... [Phys. Rev. B 78, 115103 (2008)] published Wed Sep 3, 2008.

Wave packet dynamics in a two-dimensional electron gas with spin orbit coupling: Splitting and zitterbewegung

V. Ya. Demikhovskii, G. M. Maksimova, and E. V. Frolova
We study the effect of splitting and Zitterbewegung of one- and two-dimensional electron wave packets in the semiconductor quantum well under the influence of the Rashba spin orbit coupling. Results of our investigations show that the spin orbit interaction induces dramatic qualitative changes in th ... [Phys. Rev. B 78, 115401 (2008)] published Wed Sep 3, 2008.

Proposal for the direct optical detection of pure spin currents in semiconductors

Jiang-Tao Liu and Kai Chang
We suggest a different practical scheme for the direct detection of pure spin current by using the two-color Faraday rotation of optical quantum interference process (QUIP) in a semiconductor system. We demonstrate theoretically that the Faraday rotation of QUIP depends sensitively on the spin orien ... [Phys. Rev. B 78, 113304 (2008)] published Wed Sep 3, 2008.

Double-exciton component of the cyclotron spin-flip mode in a quantum Hall ferromagnet

S. Dickmann and V. M. Zhilin
We report on the study of the cyclotron spin-flip excitation (CSFE) in a quantum Hall system at unit filling, where both the cyclotron quantum number and the spin number are changed by one compared to the ground state. The CSFE composite mode has a double-exciton component, which, even within the fi ... [Phys. Rev. B 78, 115302 (2008)] published Wed Sep 3, 2008.

Efficient iterative method for calculations of dielectric matrices

Hugh F. Wilson, Francois Gygi, and Giulia Galli
A major bottleneck in first-principles calculations of excited and spectroscopic properties of materials is the evaluation of dielectric matrices. We show that by computing a relatively small number of eigenvectors via iterative linear-response calculations, we may construct the dielectric matrix of ... [Phys. Rev. B 78, 113303 (2008)] published Wed Sep 3, 2008.

Compression curves of transition metals in the Mbar range: Experiments and projector augmented-wave calculations

Agnes Dewaele, Marc Torrent, Paul Loubeyre, and Mohamed Mezouar
The ambient temperature equations of state (EoS) of iron, cobalt, nickel, zinc, molybdenum, and silver have been measured by x-ray diffraction. These transition metals were compressed using diamond anvil cells with a helium pressure transmitting medium. The maximum pressure reached during these expe ... [Phys. Rev. B 78, 104102 (2008)] published Wed Sep 3, 2008.

[sup 19]F NMR investigation of the iron pnictide superconductor LaFeAsO[sub 0.89]F[sub 0.11]

K. Ahilan, F. L. Ning, T. Imai, A. S. Sefat, R. Jin et al.
We report on F nuclear magnetic resonance (NMR) investigation of the high-temperature superconductor LaFeAsOF (T~28 K). We demonstrate that low-frequency spin fluctuations exhibit pseudogap behavior above T. We also deduce the London penetration depth lambda from NMR line broadening below T. ... [Phys. Rev. B 78, 100501 (2008)] published Wed Sep 3, 2008.

Dynamics of vortex glass phase in strongly type-II superconductors

Qing-Hu Chen
Dynamics of vortices in strongly type-II superconductors with strong disorder is investigated within the frustrated three-dimensional XY model. For two typical models byOlsson [Phys. Rev. Lett. 91, 077002 (2003)] and Kawamura [Phys. Rev. B 68, 220502(R) (2003)], strong evidence for the finite temper ... [Phys. Rev. B 78, 104501 (2008)] published Wed Sep 3, 2008.

Correlations and order parameter at a Coulomb-crystal phase transition in a three-dimensional dimer model

Gregoire Misguich, Vincent Pasquier, and Fabien Alet
The three-dimensional classical dimer model with interactions shows an unexpected continuous phase transition between an ordered dimer crystal and a Coulomb liquid. A detailed analysis of the critical dimer and monomer correlation functions points to a subtle interplay between the fluctuations of th ... [Phys. Rev. B 78, 100402 (2008)] published Wed Sep 3, 2008.

Publisher's Note: Superconductivity of Mo[sub 3]Sb[sub 7] from first principles [Phys. Rev. B [bold 78], 060507 (2008)]

B. Wiendlocha, J. Tobola, M. Sternik, S. Kaprzyk, K. Parlinski et al.
... [Phys. Rev. B 78, 099901 (2008)] published Wed Sep 3, 2008.

Computational study of (111) epitaxially strained ferroelectric perovskites BaTiO[sub 3] and PbTiO[sub 3]

Riku Oja, Karen Johnston, Johannes Frantti, and Risto M. Nieminen
The phase transition behavior of PbTiO and BaTiO under (111) epitaxial strain is investigated using density-functional theory calculations. From tensile strains of +0.015 to compressive strains of 0.015, PbTiO undergoes phase transitions from C2 through two Cm phases and then to R3m. The total polar ... [Phys. Rev. B 78, 094102 (2008)] published Wed Sep 3, 2008.

Theoretical trend of ion exchange ability with divalent cations in hydroxyapatite

Katsuyuki Matsunaga, Hiroki Inamori, and Hidenobu Murata
First-principles calculations are performed for hydroxyapatite (Hap) in order to investigate the relative ion exchange ability with divalent cations such as Mg, Ni, Cu, Zn, Sr, Cd, Ba, and Pb. Their ionic substitutional energies are calculated from total energies of supercells and chemical potential ... [Phys. Rev. B 78, 094101 (2008)] published Wed Sep 3, 2008.

Long-range correlations in disordered graphene

K. Ziegler
The appearance of long-range correlations near the Dirac point of a Dirac-type spinor model with random vector potential is studied. These correlations originate from a spontaneously broken symmetry and their corresponding Goldstone modes. Using a strong-disorder expansion, correlation functions and ... [Phys. Rev. B 78, 125401 (2008)] published Tue Sep 2, 2008.

Publisher's Note: Quantum many-body theory of qubit decoherence in a finite-size spin bath [Phys. Rev. B [bold 78], 085315 (2008)]

Wen Yang and Ren-Bao Liu
... [Phys. Rev. B 78, 129901 (2008)] published Tue Sep 2, 2008.

Microscopics of disordered two-dimensional electron gases under high magnetic fields: Equilibrium properties and dissipation in the hydrodynamic regime

Thierry Champel, Serge Florens, and Leonie Canet
We develop in detail a formalism [as a sequel to the work of T. Champel and S. Florens, Phys. Rev. B 75, 245326 (2007)] that is well suited for treating quantum problems involving slowly varying potentials at high magnetic fields in two-dimensional electron gases. For an arbitrary smooth potential w ... [Phys. Rev. B 78, 125302 (2008)] published Tue Sep 2, 2008.

Additional levels between Landau bands due to vacancies in graphene: Towards defect engineering

A. L. C. Pereira and P. A. Schulz
We describe the effects of vacancies on the electronic properties of a graphene sheet in the presence of a perpendicular magnetic field: from a single defect to an organized vacancy lattice. An isolated vacancy is the minimal possible inner edge, showing an antidotlike behavior, which results in an ... [Phys. Rev. B 78, 125402 (2008)] published Tue Sep 2, 2008.

Influence of residual disorder on the anticrossing of Bloch modes probed in k space

N. Le Thomas, V. Zabelin, R. Houdre, M. V. Kotlyar, and T. F. Krauss
We retrieve the dispersion properties of photonic crystal waveguides near the band edge with high experimental accuracy. The dispersion diagram of the waveguide modes in the complex-valued plane is directly measured in the far field by using a Fourier space imaging technique. We show that the invest ... [Phys. Rev. B 78, 125301 (2008)] published Tue Sep 2, 2008.

Atomically resolved force microscopy images of complex surface unit cells: Ultrathin alumina film on NiAl(110)

G. H. Simon, T. Konig, M. Nilius, H.-P. Rust, M. Heyde et al.
In this Brief Report we present atomically resolved images of the ultrathin alumina film on NiAl(110). For the first time detailed images of the complex microstructure for both reflection domains have been obtained by frequency modulation dynamic force microscopy using a very stable, custom built, d ... [Phys. Rev. B 78, 113401 (2008)] published Tue Sep 2, 2008.

Sum rules and bath parametrization for quantum cluster theories

Erik Koch, Giorgio Sangiovanni, and Olle Gunnarsson
We analyze cellular dynamical mean-field theory (CDMFT) and the dynamical cluster approximation (DCA). We derive exact sum-rules for the hybridization functions and give examples for dynamical mean-field theory, CDMFT, and DCA. For impurity solvers based on a Hamiltonian, these sum rules can be used ... [Phys. Rev. B 78, 115102 (2008)] published Tue Sep 2, 2008.

Boundary criticality at the Anderson transition between a metal and a quantum spin Hall insulator in two dimensions

Hideaki Obuse, Akira Furusaki, Shinsei Ryu, and Christopher Mudry
Static disorder in a noninteracting gas of electrons confined to two dimensions can drive a continuous quantum (Anderson) transition between a metallic and an insulating state when time-reversal symmetry is preserved but spin-rotation symmetry is broken. The critical exponent nu that characterizes t ... [Phys. Rev. B 78, 115301 (2008)] published Tue Sep 2, 2008.

Atomic structure and energetics of the c-GaN(001) surface

E. Rauls, S. J. Dijkstra, and W. G. Schmidt
Density functional theory calculations are used to explore the geometry and stability of zinc-blende GaN(001). We find that the surface structure changes from a nitrogen adatom structure under nitrogen-rich conditions to a gallium contracted adlayer structure under gallium-rich conditions. Nitrogen ... [Phys. Rev. B 78, 113302 (2008)] published Tue Sep 2, 2008.

Structural and electronic properties of SrFeO[sub 2] from first principles

J. M. Pruneda, Jorge Iniguez, Enric Canadell, Hiroshi Kageyama, and Mikio Takano
We report on a first-principles study of SrFeO, an infinite-layer oxide with Fe atoms in a perfect square-planar coordination down to essentially 0 K. Our results reveal that this striking behavior relies on the double occupation of the 3d orbitals of high-spin Fe. Such an electronic state results f ... [Phys. Rev. B 78, 115101 (2008)] published Tue Sep 2, 2008.

Conceptual molecular quantum phase transistor based on first-principles quantum transport calculations

Zekan Qian, Rui Li, Xingyu Zhao, Shimin Hou, and Stefano Sanvito
A conceptual molecular phase-coherent transistor is proposed based on first-principles quantum transport calculations. The device is formed by two molecules connected via a one-dimensional wire and it is operated by gating the interconnect between the molecules and exploiting quantum-mechanical inte ... [Phys. Rev. B 78, 113301 (2008)] published Tue Sep 2, 2008.

Impulsive excitation of coherent magnons and phonons by subpicosecond laser pulses in the weak ferromagnet FeBO[sub 3]

A. M. Kalashnikova, A. V. Kimel, R. V. Pisarev, V. N. Gridnev, P. A. Usachev et al.
Coherent magnons and phonons are excited by subpicosecond laser pulses in the weak ferromagnet FeBO. Impulsive stimulated Raman scattering (ISRS) is proven to be the microscopic mechanism of the excitation. It is shown that coherent magnons can be excited by both linearly and circularly polarized la ... [Phys. Rev. B 78, 104301 (2008)] published Tue Sep 2, 2008.

Raman scattering investigation across the magnetic and metal-insulator transition in rare earth nickelate RNiO[sub 3] (R = Sm, Nd) thin films

C. Girardot, J. Kreisel, S. Pignard, N. Caillault, and F. Weiss
We report a temperature-dependent Raman scattering investigation of thin-film rare earth nickelates SmNiO, NdNiO, and SmNdNiO which present a metal-to-insulator (MI) transition at T and an antiferromagnetic-paramagnetic Neel transition at T. Our results provide evidence that all investigated samples ... [Phys. Rev. B 78, 104101 (2008)] published Tue Sep 2, 2008.

Broadband ferromagnetic resonance of Ni[sub 81]Fe[sub 19] wires using a rectifying effect

A. Yamaguchi, K. Motoi, A. Hirohata, H. Miyajima, Y. Miyashita et al.
The broadband ferromagnetic resonance (FMR) measurement has been carried out by using a rectifying effect in two sets of NiFe wires. One wire is deposited on the middle strip line of the coplanar waveguide (CPW) and another is deposited between two strip lines of the CPW, measuring the FMR induced b ... [Phys. Rev. B 78, 104401 (2008)] published Tue Sep 2, 2008.

Verwey transition in Fe[sub 3]O[sub 4] at high pressure: Quantum critical point at the onset of metallization

J. Spalek, A. Kozlowski, Z. Tarnawski, Z. Kakol, Y. Fukami et al.
We provide evidence for the existence of a quantum critical point at the metallization of magnetite FeO at pressure p[approximate]8 GPa. We show that the present ac magnetic-susceptibility data support earlier resistivity data. The Verwey temperature scales with pressure T~(1p/p) with nu~1/3. The r ... [Phys. Rev. B 78, 100401 (2008)] published Tue Sep 2, 2008.

Temperature dependence of nonlinear auto-oscillator linewidths: Application to spin-torque nano-oscillators

V. S. Tiberkevich, A. N. Slavin, and Joo-Von Kim
The temperature dependence of the generation linewidth for an auto-oscillator with a nonlinear frequency shift is calculated. It is shown that the frequency nonlinearity creates a finite correlation time tau=1/Gamma for the phase fluctuations. In the low-temperature limit in which the spectral linew ... [Phys. Rev. B 78, 092401 (2008)] published Tue Sep 2, 2008.

Barrier crossing to the small Holstein polaron regime

Peter Hamm and G. P. Tsironis
We investigate the dimensionality effects of the Holstein polaron from the fully quantum regime, where the crossover between large and small polaron solutions is known to be continuous in all dimensions, into the limit described by the semiclassical discrete nonlinear Schrodinger (DNLS) equation, wh ... [Phys. Rev. B 78, 092301 (2008)] published Tue Sep 2, 2008.

Neutron diffraction study of the magnetic structure of the superconducting Ru-1222-type ruthenocuprate RuSr[sub 2]Y[sub 1.5]Ce[sub 0.5]Cu[sub 2]O[sub 10 - delta]: Evidence for long-range antiferromagnetic order

A. C. Mclaughlin, I. Felner, and V. P. S. Awana
A neutron diffraction study on the superconducting Ru-1222 ruthenocuprate RuSrYCeCuO (T=35 K) prepared by the high-pressure high-temperature technique reveals long-range antiferromagnetic order below 140 K. Neighboring spins are antiparallel on the ab plane but both antiferromagnetic and ferromagne ... [Phys. Rev. B 78, 094501 (2008)] published Tue Sep 2, 2008.

Direct determination of resonance phase shifts of soft x-ray diffraction in thin films by momentum-transfer-sensitive three-wave interference

H.-H. Wu, Y.-R. Lee, Y.-Y. Chang, C.-H. Chu, Y.-W. Tsai et al.
A method for direct determination of resonance phase shifts in a (001) CdTe/InSb thin-film system is developed using soft x-ray three-wave resonance diffraction. At the (002) Bragg peaks of CdTe and InSb, two inversion-symmetry related three-wave diffractions are systematically identified according ... [Phys. Rev. B 78, 092101 (2008)] published Tue Sep 2, 2008.

Atomic and energy structure of InAs/AlAs quantum dots

T. S. Shamirzaev, A. V. Nenashev, A. K. Gutakovskii, A. K. Kalagin, K. S. Zhuravlev et al.
The atomic structure and energy spectrum of InAs quantum dots (QDs) in an AlAs matrix have been experimentally studied by transmission electron microscopy (TEM) and steady-state photoluminescence (PL) combined with computational work. The degree of intermixing of InAs and AlAs has been investigated ... [Phys. Rev. B 78, 085323 (2008)] published Fri Aug 29, 2008.

Role of oxygen defects in diluted Mn:Ge

A. Continenza and G. Profeta
The effects of spurious oxygen atoms on the electronic and magnetic properties of Mn-doped germanium are studied using ab initio calculations. Several different sites together with the formation of some defects complexes are investigated and analyzed looking at the energetics, structure, and electro ... [Phys. Rev. B 78, 085215 (2008)] published Fri Aug 29, 2008.

Mechanism of ferromagnetism in nitrogen-doped ZnO: First-principle calculations

L. Shen (沈雷), R. Q. Wu, H. Pan, G. W. Peng, M. Yang et al.
Based on our first-principle calculations, ZnO doped by a nonmagnetic 2p light element (N) is predicted to be ferromagnetic. The local magnetic moments that are mainly localized on doped N atoms introduced total moments of 1.0[mu]/atom. The long-range magnetic coupling of N-doped ZnO can be attribut ... [Phys. Rev. B 78, 073306 (2008)] published Fri Aug 29, 2008.

Microscopic mechanism of dipole layer formation at the pentacene/Si interface

Hojin Jeong, Duk Yong Jung, and Han Woong Yeom
We elucidate the microscopic mechanism of the dipole layer formation at the prototypical organic/inorganic interface of pentacene/Si(001) by first-principles calculations and photoelectron spectroscopy. Both theory and experiments indicate a positive dipole layer formation against the simple charge- ... [Phys. Rev. B 78, 073305 (2008)] published Fri Aug 29, 2008.

Calculation of current-induced torque from spin continuity equation

Gen Tatara and Peter Entel
Current-induced torque is formulated based on the spin continuity equation. The formulation does not rely on the assumption of separation of local spin and charge degrees of freedom, in contrast to approaches based on the s-d model or mean-field approximation of itinerant ferromagnetism. This method ... [Phys. Rev. B 78, 064429 (2008)] published Fri Aug 29, 2008.

Effects of nonmagnetic scatterers on the magnetic coherence length in the mixed state of type-II superconductors

R. Laiho, M. Safonchik, and K. B. Traito
Influence of impurities on magnetic coherence length xi in mixed state of type-II superconductors is investigated in framework of quasiclassical theory. Nonmonotonic magnetic-field dependence of xi(B) is found. Increasing of the scattering rate results in decreasing of xi making the xi(B) curve flat ... [Phys. Rev. B 78, 064521 (2008)] published Fri Aug 29, 2008.

Oxygen-molecule spin-nanotubes constructed by physisorption into a nanoporous medium

Masaki Mito, Noritoshi Shinto, Yuki Komorida, Takayuki Tajiri, Hiroyuki Deguchi et al.
We succeeded in controlling gas-liquid-solid transitions and in constructing spin-nanotubes (SNTs) based on antiferromagnetic correlations by physisorbing oxygen molecules (O) into the nanosize pores of a mesoporous medium MCM-41 while also manipulating the adsorption quantity. The phase diagram of ... [Phys. Rev. B 78, 064428 (2008)] published Fri Aug 29, 2008.

Attempt frequency of magnetization in nanomagnets with thin-film geometry

Hong-Ju Suh, Changehoon Heo, Chun-Yeol You, Woojin Kim, Taek-Dong Lee et al.
Solving the stochastic Landau-Lifshitz-Gilbert equation numerically, we investigate the effect of the potential landscape on the attempt frequency of magnetization in nanomagnets with the thin-film geometry. Numerical estimates of the attempt frequency are analyzed in comparison with theoretical pre ... [Phys. Rev. B 78, 064430 (2008)] published Fri Aug 29, 2008.

Strong-coupling theory of the universal linear temperature dependence of the nodal Fermi velocity in layered cuprates

Andrey Chubukov and Ilya Eremin
We explain the recently observed linear temperature dependence of the nodal Fermi velocity v(T) in nearly optimally doped cuprates. We argue that it originates from electron-electron interaction and it is a fundamental property of an arbitrary two-dimensional (2D) Fermi liquid. We consider a spin-fe ... [Phys. Rev. B 78, 060509 (2008)] published Fri Aug 29, 2008.

Low-temperature elastic moduli of a Pd-based metallic glass showing positive phonon dispersion

T. Ichitsubo, E. Matsubara, K. Miyagi, W. Itaka, K. Tanaka et al.
We have recently shown that the sound velocity obtained from the inelastic x-ray scattering (IXS) measurement exceeds the ultrasonic wave velocity of a Pd-based metallic glass in a rigid glass state far below its glass transition temperature. Here we report that no obvious evidence of faster process ... [Phys. Rev. B 78, 052202 (2008)] published Fri Aug 29, 2008.

Anisotropy in two-dimensional arrays of collinear in-plane rotated identical particles with arbitrary charge or polarization distribution

N. Mikuszeit, J. J. de Miguel, and R. Miranda
As the size and separation between nanometric objects arranged on a two-dimensional lattice become progressively smaller, the influence of interparticle coupling increases to the point that it may dominate the system's collective behavior. In this paper, a simple method to calculate isotropic and an ... [Phys. Rev. B 78, 054448 (2008)] published Fri Aug 29, 2008.

Current driven dynamics of domain walls constrained in ferromagnetic nanopillars

Matteo Franchin, Thomas Fischbacher, Giuliano Bordignon, Peter de Groot, and Hans Fangohr
We investigate the effects of an electric current on the domain wall formed inside a cylindrical ferromagnetic nanopillar as a consequence of the pinning of the magnetization at its ends. We first present the results of three-dimensional and one-dimensional micromagnetic simulations and show that th ... [Phys. Rev. B 78, 054447 (2008)] published Fri Aug 29, 2008.

Evidence for unusual superconducting correlations coexisting with stripe order in La(1.875)Ba(0.125)CuO(4). (arXiv:0809.0711v1 [cond-mat.supr-con])

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Emission of Terahertz Radiation from SiC. (arXiv:0809.0756v1 [cond-mat.mtrl-sci])

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Properties of anisotropic magnetic impurities on surfaces. (arXiv:0809.0759v1 [cond-mat.str-el])

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Lattice models for non-Fermi liquid metals. (arXiv:0809.0762v1 [cond-mat.str-el])

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Fine structure in the electronic density of states of Al-Ni-Co decagonal quasicrystal from ultrafast time-resolved optical reflectivity. (arXiv:0809.0764v1 [cond-mat.other])

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Coherent control of dressed matter waves. (arXiv:0809.0768v1 [cond-mat.other])

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Effects of Bending on Raman-active Vibration Modes of Carbon Nanotubes. (arXiv:0809.0769v1 [cond-mat.mtrl-sci])

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Evolution of an Unconventional Superconducting State inside the Antiferromagnetic Phase of CeNiGe$_3$ under Pressure: a $^{73}$Ge-Nuclear-Quadrupole-Resonance Study. (arXiv:0809.0770v1 [cond-mat.str-el])

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Visibility of Cold Atomic Gases in Optical Lattices for Finite Temperatures. (arXiv:0809.0771v1 [cond-mat.stat-mech])

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Semiclassical theory of the trapped quasi-2D Bose gas. (arXiv:0809.0747v1 [cond-mat.other])

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van der Waals dispersion power laws for cleavage, exfoliation and stretching in multi-scale, layered systems. (arXiv:0809.0736v1 [cond-mat.mtrl-sci])

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Effect of Zn substitution for Cu on Ca$_{2-x}$Na$_{x}$CuO$_{2}$Cl$_{2}$ near the hole concentration of 1/8 per Cu. (arXiv:0809.0735v1 [cond-mat.supr-con])

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