Magnetic-field induced quantum-size cascades in superconducting nanowires
A. A. Shanenko, M. D. Croitoru, and F. M. Peeters
In high-quality nanowires, quantum confinement of the transverse electron motion splits the band of single-electron states in a series of subbands. This changes in a qualitative way the scenario of the magnetic-field induced superconductor-to-normal transition. We numerically solve the Bogoliubov-de ... [Phys. Rev. B 78, 024505 (2008)] published Thu Jul 3, 2008.
Structure and magnetism of Fe-doped SnO[sub 2] nanoparticles
R. Adhikari, A. K. Das, D. Karmakar, T. V. Chandrasekhar Rao, and J. Ghatak
SnO nanoparticles doped with Fe of different concentrations were synthesized by a chemical coprecipitation method. After calcination at 600 degrees C, the samples were characterized using x-ray diffraction (XRD), transmission electron microscope (TEM), and superconducting quantum interference devic ... [Phys. Rev. B 78, 024404 (2008)] published Thu Jul 3, 2008.
Quantum interference and weak localization effects in the interlayer magnetoresistance of layered metals
Malcolm P. Kennett and Ross H. McKenzie
Studies of angle-dependent magnetoresistance oscillations (AMRO) in the interlayer conductivity of layered metals have generally considered semiclassical electron transport. We consider a quantum correction to the semiclassical conductivity that arises from what can be described as an interlayer Coo ... [Phys. Rev. B 78, 024506 (2008)] published Thu Jul 3, 2008.
Tunnel-barrier-enhanced dc voltage signals induced by magnetization dynamics in magnetic tunnel junctions
Yaroslav Tserkovnyak, T. Moriyama, and John Q. Xiao
We theoretically study the recently observed tunnel-barrier-enhanced dc voltage signals generated by magnetization precession in magnetic tunnel junctions. While the spin pumping is suppressed by the high tunneling impedance, two complementary processes are predicted to result in a sizable voltage g ... [Phys. Rev. B 78, 020401 (2008)] published Thu Jul 3, 2008.
Magnetism of isolated cadmium atoms in vacancy-associated sites in nickel
W.-D. Zeitz, R. Dogra, A. P. Byrne, S. K. Shrestha, A. V. J. Edge et al.
The magnetic hyperfine fields of Cd guest atoms in nickel have been measured by perturbed angular correlation spectroscopy with an unprecedented precision. The experiments exhibit the well-known oscillations which have been attributed to the substitutional and the cubic C-site of Cd in nickel, but a ... [Phys. Rev. B 78, 014406 (2008)] published Thu Jul 3, 2008.
Angular dependence and origin of asymmetric magnetization reversal in exchange-biased Fe/FeF[sub 2](110)
A. Tillmanns, S. Oertker, B. Beschoten, G. Guntherodt, J. Eisenmenger et al.
Asymmetric magnetization reversal in exchange-biased Fe/FeF has been analyzed by magneto-optic Kerr loops transverse to the measuring field. Noncollinear cooling-field and measuring-field directions yield a complex phase diagram of distinct transverse reversal modes. The phase diagram is simulated b ... [Phys. Rev. B 78, 012401 (2008)] published Thu Jul 3, 2008.
Effect of inversion symmetry on the incommensurate order in multiferroic RMn[sub 2]O[sub 5] (R = rare earth)
A. B. Harris, M. Kenzelmann, Amnon Aharony, and O. Entin-Wohlman
Starting from the irreducible representations of the group of the wave vector, we construct the spin-wave functions consistent with inversion symmetry, neglected in the usual representation analysis. We obtain the relation between the basis functions of different members of the star of the wave vect ... [Phys. Rev. B 78, 014407 (2008)] published Thu Jul 3, 2008.
Two circular-rotational eigenmodes and their giant resonance asymmetry in vortex gyrotropic motions in soft magnetic nanodots
Ki-Suk Lee and Sang-Koog Kim
We found, by micromagnetic numerical and analytical calculations, that the clockwise (CW) and counterclockwise (CCW) circular-rotational motions of a magnetic vortex core in a soft magnetic circular nanodot are the elementary eigenmodes existing in the gyrotropic motion with respect to the correspon ... [Phys. Rev. B 78, 014405 (2008)] published Thu Jul 3, 2008.
Relation between magnetoresistance and nanostructure of current-perpendicular-to-plane giant-magnetoresistance film with current-confined-path nano-oxide layer
Hiromi Yuasa, Michiko Hara, and Hideaki Fukuzawa
Nanostructure of a current-perpendicular-to-plane giant-magnetoresistance film with a current-confined-path (CCP) nano-oxide layer was analyzed by high-resolution transmission electron microscopy and three-dimensional atom probe. It was found that the CCP of a film with a higher magnetoresistance (M ... [Appl. Phys. Lett. 92, 262509 (2008)] published Thu Jul 3, 2008.
Altering the Superconductor Transition Temperature by Domain-Wall Arrangements in Hybrid Ferromagnet-Superconductor Structures
L. Y. Zhu, T. Y. Chen, and C. L. Chien
The [Co/Pt]/Nb/[Co/Pt] hybrids with perpendicular magnetic anisotropy reveal enhanced superconductivity with the presence, and the arrangements, of domain walls, where superconductivity persists. An in-plane field can manipulate the domain walls from labyrinth to stripe patterns and drive the hybrid ... [Phys. Rev. Lett. 101, 017004 (2008)] published Thu Jul 3, 2008.
Tuning the Pressure-Induced Superconducting Phase in Doped CeRhIn[sub 5]
L. Mendonca Ferreira, T. Park, V. Sidorov, M. Nicklas, E. M. Bittar et al.
Pressure- and temperature-dependent heat capacity and electrical resistivity experiments on Sn- and La-doped CeRhIn are reported for two samples with specific concentrations, CeLaRhIn and CeRhInSn, which present the same T=2.8 K. The obtained P-T phase diagrams for doped CeRhIn compared to that for ... [Phys. Rev. Lett. 101, 017005 (2008)] published Thu Jul 3, 2008.
ac Magnetization Transport and Power Absorption in Nonitinerant Spin Chains
Bjorn Trauzettel, Pascal Simon, and Daniel Loss
We investigate the ac transport of magnetization in nonitinerant quantum systems such as spin chains described by the XXZ Hamiltonian. Using linear response theory, we calculate the ac magnetization current and the power absorption of such magnetic systems. Remarkably, the difference in the exchange ... [Phys. Rev. Lett. 101, 017202 (2008)] published Thu Jul 3, 2008.
Magnetization decay in neutron irradiated MgB[sub 2] bulk samples
C. Tarantini, P. Manfrinetti, A. Palenzona, M. Putti, C. Ferdeghini et al.
In this paper the magnetization decay behavior of neutron irradiated MgB bulk samples and an estimate of the strength of the introduced pinning centers are presented. The magnetization decay measurements appear much more complex than usual, in fact, they may be logarithmic or not, depending on the v ... [J. Appl. Phys. 104, 013903 (2008)] published Thu Jul 3, 2008.
Helicity asymmetry of optically pumped NMR spectra in GaAs
Patrick J. Coles
The origin of sigma asymmetries in the optically pumped nuclear magnetic resonance (NMR) signal and hyperfine shift in GaAs is derived analytically and tested experimentally. The ratio of the optically pumped to the equilibrium electron polarizations is a key parameter in determining both asymmetrie ... [Phys. Rev. B 78, 033201 (2008)] published Wed Jul 2, 2008.
Muon-spin rotation measurements of the penetration depth of the Mo[sub 3]Sb[sub 7] superconductor
R. Khasanov, P. W. Klamut, A. Shengelaya, Z. Bukowski, I. M. Savic et al.
Measurements of the magnetic-field penetration depth lambda in superconductor MoSb (T~=2.1 K) were carried out by means of muon-spin rotation. The absolute values of lambda, the Ginzburg-Landau parameter kappa, and the first H and the second H critical fields at T=0 are lambda(0)=720(100) nm, kapp ... [Phys. Rev. B 78, 014502 (2008)] published Wed Jul 2, 2008.
Fate of partial order on trillium and distorted windmill lattices
Sergei V. Isakov, John M. Hopkinson, and Hae-Young Kee
The classical Heisenberg model on the trillium and distorted windmill lattices exhibits a degenerate ground state within large-N theory where the degenerate wave vectors form a surface and line, in three-dimensional space, respectively. We name such states partially ordered to represent the existenc ... [Phys. Rev. B 78, 014404 (2008)] published Wed Jul 2, 2008.
Engineering exotic phases for topologically protected quantum computation by emulating quantum dimer models
A. Fabricio Albuquerque, Helmut G. Katzgraber, Matthias Troyer, and Gianni Blatter
We use a nonperturbative extended contractor renormalization (ENCORE) method for engineering quantum devices for the implementation of topologically protected quantum bits described by an effective quantum dimer model on the triangular lattice. By tuning the couplings of the device, topological prot ... [Phys. Rev. B 78, 014503 (2008)] published Wed Jul 2, 2008.
Magnetically induced ferroelectricity in orthorhombic manganites: Microscopic origin and chemical trends
Kunihiko Yamauchi, Frank Freimuth, Stefan Blugel, and Silvia Picozzi
The microscopic origin of the magnetically driven ferroelectricity in collinear E-type antiferromagnetic (AFM-E) orthorhombic manganites is explained by means of first-principles Wannier functions. We show that the polarization is mainly determined by the asymmetric electron hopping of orbitally pol ... [Phys. Rev. B 78, 014403 (2008)] published Wed Jul 2, 2008.
Spin-dependent processes at the crystalline Si-SiO[sub 2] interface at high magnetic fields
D. R. McCamey, G. W. Morley, H. A. Seipel, L. C. Brunel, J. van Tol et al.
An experimental study on the nature of spin-dependent excess charge-carrier transitions at the interface between (111)-oriented phosphorous-doped ([P][approximate]10 cm) crystalline silicon and silicon dioxide at high magnetic field (B[approximate]8.5 T) is presented. Electrically detected magneti ... [Phys. Rev. B 78, 045303 (2008)] published Wed Jul 2, 2008.
Quantum oscillations in the mixed state of d-wave superconductors
Ashot Melikyan and Oskar Vafek
We show that the low-energy density of quasiparticle states in the mixed state of ultraclean d-wave superconductors exhibits quantum oscillations even in the regime where the cyclotron frequency [h-bar]omega<
Ising and spin orders in the iron-based superconductors
Cenke Xu, Markus Muller, and Subir Sachdev
Motivated by recent neutron scattering experiments, we study the ordering of spins in the iron-based superconductors LaFeAs(OF), assuming them in proximity to a Mott insulator in the phase diagram. The ground state of the parent system with x=0 is a spin-density wave with ordering wave vector Q-vect ... [Phys. Rev. B 78, 020501 (2008)] published Wed Jul 2, 2008.
Influence of asymmetry on vortex nucleation and annihilation in submicroscaled permalloy disk array
Kuo-Ming Wu, Lance Horng, Jia-Feng Wang, Jong-Ching Wu, Yin-Hao Wu et al.
Magnetic properties of vortex nucleation, annihilation, and switching field distribution (SFD) in NiFe disk arrays, where the elements are with 300 nm diameter and different degrees of asymmetry, were investigated through measurements and simulations of hysteresis loop. The nucleation and annihilat ... [Appl. Phys. Lett. 92, 262507 (2008)] published Wed Jul 2, 2008.
Multiferroicity in the spin-1/2 quantum matter of LiCu[sub 2]O[sub 2]
A. Rusydi, I. Mahns, S. Muller, M. Rubhausen, S. Park et al.
Multiferroicity in LiCuO single crystals is studied using resonant soft x-ray magnetic scattering, hard x-ray diffraction, heat capacity, magnetic susceptibility, and electrical polarization. Two magnetic transitions are found at 24.6 K (T) and 23.2 K (T). Our data are consistent with a sinusoidal ... [Appl. Phys. Lett. 92, 262506 (2008)] published Wed Jul 2, 2008.
Size dependence of intrinsic spin transfer switching current density in elliptical spin valves
R. Heindl, S. E. Russek, T. J. Silva, W. H. Rippard, J. A. Katine et al.
We studied current-induced magnetization reversal in elliptical spin valves with CoFeB free layers. The data obtained from high-speed pulsed switching experiments showed that the intrinsic switching current densities were size dependent and 50%100% higher than predicted by a single-domain model. Mic ... [Appl. Phys. Lett. 92, 262504 (2008)] published Wed Jul 2, 2008.
Magnetoelectric behavior of BaTiO[sub 3] films directly grown on CoFe[sub 2]O[sub 4] ceramics
Jing Wang, Yi Zhang, Jing Ma, Yuanhua Lin, and C. W. Nan
BaTiO films were grown on highly dense CoFeO ceramics via pulsed laser deposition. Microstructural characterization showed that polycrystalline BaTiO thin films with grain size of about 70 nm were grown on the CoFeO ceramics. BaTiO films showed good ferroelectric feature. An obvious magnetoelectric ... [J. Appl. Phys. 104, 014101 (2008)] published Wed Jul 2, 2008.
Magnetoelectric effect in rare earth ferrites, LnFe[sub 2]O[sub 4]
Claudy Rayan Serrao, Jyoti Ranjan Sahu, K. Ramesha, and C. N. R. Rao
Dielectric and magnetic properties of selected rare earth ferrites, LnFeO (Ln=Y,Er,Yb), have been investigated. All these materials show ferroelectricity near the ferrimagnetic transition temperature around 250 K. More importantly, they exhibit a change in the dielectric behavior on the application ... [J. Appl. Phys. 104, 016102 (2008)] published Wed Jul 2, 2008.
Investigation on the intergranular interaction of the soft magnetic granular films by delta M(H) curves
Dongsheng Yao, Shihui Ge, Xueyun Zhou, and Huaping Zuo
(FeCo)(SiO) granular films with various volume fraction (x) of FeCo alloy were fabricated by magnetron sputtering, and the interaction between granules was explored by deltaM(H) plots. Research results show that deltaM(H) is positive for the samples in a wide range of 0.42
High Energy Dispersion Relations for the High Temperature Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub 8] Superconductor from Laser-Based Angle-Resolved Photoemission Spectroscopy
Wentao Zhang, Guodong Liu, Jianqiao Meng, Lin Zhao, Haiyun Liu et al.
Laser-based angle-resolved photoemission spectroscopy measurements have been carried out on the high energy electron dynamics in BiSrCaCuO high temperature superconductor. Our superhigh resolution data, momentum-dependent measurements, and complete analysis provide important information to judge the ... [Phys. Rev. Lett. 101, 017002 (2008)] published Wed Jul 2, 2008.
Microscopic Evidence of Spin State Order and Spin State Phase Separation in Layered Cobaltites RBaCo[sub 2]O[sub 5.5] with R = Y, Tb, Dy, and Ho
H. Luetkens, M. Stingaciu, Yu. G. Pashkevich, K. Conder, E. Pomjakushina et al.
We report muon-spin relaxation measurements on the magnetic structures of RBaCoO with R=Y, Tb, Dy, and Ho. Three different phases, one ferrimagnetic and two antiferromagnetic, are identified below 300 K. They consist of different ordered spin state arrangements of high-, intermediate-, and low-spin ... [Phys. Rev. Lett. 101, 017601 (2008)] published Wed Jul 2, 2008.
Publisher's Note: Observation of an ultrahigh-temperature ferromagnetic-like transition in iron-contaminated multiwalled carbon nanotube mats [Phys. Rev. B [bold 77], 245433 (2008)]
Guo-meng Zhao and Pieder Beeli
... [Phys. Rev. B 78, 049901 (2008)] published Tue Jul 1, 2008.
Classical dynamics of resonantly modulated large-spin systems
C. Hicke and M. I. Dykman
We study the classical dynamics of resonantly modulated large-spin systems in a strong magnetic field, where the Zeeman energy exceeds the anisotropy energy. We show that these systems have special symmetry. It leads to characteristic nonlinear effects. They include abrupt switching between magnetiz ... [Phys. Rev. B 78, 024401 (2008)] published Tue Jul 1, 2008.
Self-consistent solution for proximity effect and Josephson current in ballistic graphene SNS Josephson junctions
Annica M. Black-Schaffer and Sebastian Doniach
We use a tight-binding Bogoliubovde Gennes (BdG) formalism to self-consistently calculate the proximity effect, Josephson current, and local density of states in ballistic graphene superconductor-normal conductor-superconductor (SNS) Josephson junctions. Both short and long junctions, with respect t ... [Phys. Rev. B 78, 024504 (2008)] published Tue Jul 1, 2008.
High-frequency dynamics of hybrid oxide Josephson heterostructures
P. Komissinskiy, G. A. Ovsyannikov, K. Y. Constantinian, Y. V. Kislinski, I. V. Borisenko et al.
We summarize our results on Josephson heterostructures Nb/Au/YBaCuO that combine conventional (S) and oxide high-T superconductors with a dominant d-wave symmetry of the superconducting order parameter (D). The heterostructures were fabricated on (001) and (1 1 20) YBaCuO films grown by pulsed laser ... [Phys. Rev. B 78, 024501 (2008)] published Tue Jul 1, 2008.
Island formation in disordered superconducting thin films at finite magnetic fields
Yonatan Dubi, Yigal Meir, and Yshai Avishai
It has been predicted theoretically and observed experimentally that disorder leads to spatial fluctuations in the superconducting (SC) gap. Areas where SC correlations are finite, coined SC islands, were shown experimentally to persist into the insulating side of the superconductor-insulator transi ... [Phys. Rev. B 78, 024502 (2008)] published Tue Jul 1, 2008.
Kinetics of nonequilibrium quasiparticle tunneling in superconducting charge qubits
M. D. Shaw, R. M. Lutchyn, P. Delsing, and P. M. Echternach
We directly observe low-temperature nonequilibrium quasiparticle tunneling in charge qubits based on the single-Cooper-pair box. We measure even- and odd-state dwell-time distributions as a function of temperature, and interpret these results using a kinetic theory. While the even-state lifetime is ... [Phys. Rev. B 78, 024503 (2008)] published Tue Jul 1, 2008.
Magnetism in small bimetallic Mn-Co clusters
Shreemoyee Ganguly, Mukul Kabir, Soumendu Datta, Biplab Sanyal, and Abhijit Mookerjee
Effects of alloying on the electronic and magnetic properties of MnCo (x+y=n=25; x=0n) and MnCo nanoalloy clusters are investigated using the density-functional theory. Unlike the bulk alloy, the Co-rich clusters are found to be ferromagnetic and the magnetic moment increases with Mn concentratio ... [Phys. Rev. B 78, 014402 (2008)] published Tue Jul 1, 2008.
Structural and magnetic characterization of multiferroic (BiFeO[sub 3])[sub 1 - x](PbTiO[sub 3])[sub x] solid solutions
W.-M. Zhu, H.-Y. Guo, and Z.-G. Ye
A series of multiferroic (1x)BiFeOxPbTiO solid solution ceramics were prepared by solid-state reactions. Structural characterization by x-ray diffraction reveals the existence of a morphotropic phase boundary (MPB) region in this system in which a tetragonal, a rhombohedral, and an orthorhombic phas ... [Phys. Rev. B 78, 014401 (2008)] published Tue Jul 1, 2008.
Effective action, magnetic excitations, and quantum fluctuations in lightly doped single-layer cuprates
Alexander I. Milstein and Oleg P. Sushkov
We consider the extended two-dimensional t-t-t-J model at zero temperature. Parameters of the model corresponds to doping by holes. Using the low doping effective action, we demonstrate that the system can: (1) preserve the long-range collinear antiferromagnetic order, (2) lead to a spin spiral stat ... [Phys. Rev. B 78, 014501 (2008)] published Tue Jul 1, 2008.
Selective polarization transfer using a single rf field
Eddy R. Rey Castellanos, Dominique P. Frueh, and Julien Wist
NMR is a popular and mature technique used in fields as diverse as chemistry, biology, or material science. One reason for this versatility lies in its ability to correlate the nuclei that are present in one molecule to another. This provides the researcher with correlation maps allowing for studies ... [J. Chem. Phys. 129, 014504 (2008)] published Tue Jul 1, 2008.
Selective polarization transfer using a single rf field
Eddy R. Rey Castellanos, Dominique P. Frueh, and Julien Wist
NMR is a popular and mature technique used in fields as diverse as chemistry, biology, or material science. One reason for this versatility lies in its ability to correlate the nuclei that are present in one molecule to another. This provides the researcher with correlation maps allowing for studies ... [J. Chem. Phys. 129, 014504 (2008)] published Tue Jul 1, 2008.
Pressure-induced metallization and resonant Raman scattering in Zn[sub 1 - x]Mn[sub x]Te
Y. C. Lin, W. C. Fan, C. H. Chiu, F. K. Ke, S. L. Yang et al.
Pressure-induced resonant Raman scattering is adopted to analyze the zone-center optical phonon modes and crystal characteristics of ZnMnTe (0[less, double equals]x[less, double equals]0.26) thin films. The pressure (Pt) at which the semiconducting undergoes a transition to the metallic phase decli ... [J. Appl. Phys. 104, 013503 (2008)] published Tue Jul 1, 2008.
A new approach to electron-spin resonance absorption line shape function
Nam Lyong Kang and Sang Don Choi
We derive a new electron-spin resonance spectrum formula utilizing a quantum-statistical projection technique. The line shape factor appearing in the susceptibility tensor contains the many-body effects for electrons more realistically. It thus becomes possible to explain, in an organized way, all e ... [J. Math. Phys. 49, 073501 (2008)] published Tue Jul 1, 2008.
Absence of Broken Time-Reversal Symmetry in the Pseudogap State of the High Temperature La[sub 2-x]Sr[sub x]CuO[sub 4] Superconductor from Muon-Spin-Relaxation Measurements
G. J. MacDougall, A. A. Aczel, J. P. Carlo, T. Ito, J. Rodriguez et al.
We have performed zero-field muon-spin-relaxation measurements on single crystals of LaSrCuO to search for spontaneous currents in the pseudogap state. By comparing measurements on materials across the phase diagram, we put strict upper limits on any possible time-reversal symmetry breaking fields t ... [Phys. Rev. Lett. 101, 017001 (2008)] published Tue Jul 1, 2008.
Thermal stability of synthetic antiferromagnet and hard magnet coupled spin valves
Zeenath R. Tadisina, Subhadra Gupta, Patrick LeClair, and Tim Mewes
The magnetic properties of current-in-plane (CIP) giant magnetoresistive (GMR) spin valves employing synthetic antiferromagnet (SAF) pinning have been investigated. The conventional spin valve structure, with a ferromagnetic (FM) layer pinned by an antiferromagnet (AFM) layer, exhibits high electric ... [J. Vac. Sci. Technol. A 26, 735 (2008)] published Mon Jun 30, 2008.
High magnetization FeCo/Pd multilayers
M. J. Walock, H. Ambaye, M. Chshiev, F. R. Klose, W. H. Butler et al.
We have fabricated multilayer samples with varying superlattice periodicity and interlayer thicknesses to determine the nature of the enhanced moment in this intriguing thin film system. Magnetic characterization experiments show an enhanced magnetic moment in the multilayers as compared to a single ... [J. Vac. Sci. Technol. A 26, 731 (2008)] published Mon Jun 30, 2008.
Simulation of the magnetization reversal of an ensemble of single-domain particles in measurements with a continuous sweep of the magnetic field or temperature
A. A. Timopheev, V. M. Kalita, and S. M. Ryabchenko
An analysis is made of the various protocols of magnetostatic measurements for an ensemble of uniaxial single-domain particles oriented with easy axes along the magnetic field. It is shown that an important role in the magnetization reversal process is played by the continuous sweep of the magnetic ... [Low Temp. Phys. 34, 446 (2008)] published Mon Jun 30, 2008.
Magnetic properties of La[sub 0.7]Sr[sub 0.3]MnO[sub 3] nanopowders
V. M. Kalita, A. F. Lozenko, S. M. Ryabchenko, A. A. Timopheeev, R. A. Trotsenko et al.
The peculiarities of the magnetization of a nanopowder (particle size 12 nm) of the manganite LaSrMnO are investigated. It is shown that for temperatures below the Curie point the magnetization of the powder is of the ferromagnetic type with a relatively small value of the remanent magnetization. T ... [Low Temp. Phys. 34, 436 (2008)] published Mon Jun 30, 2008.
Peculiarities of the spontaneous and magnetic-field-induced magnetically ordered phases in alloys of the Mn[sub 2 - x]Fe[sub x]As[sub 0.5]P[sub 0.5] system
V. I. Val'kov, D. V. Varyukhin, and A. V. Golovchan
The phase diagram of the system MnFeAsP is investigated experimentally and theoretically. The existence of an antiferromagnetic phase for alloys with x<0.7 is revealed. It is shown that in the region 0.5
Magnetoelectric states of TbMnO[sub 3] in magnetic fields of different directions
I. E. Chupis
A phenomenological analysis of the magnetoelectric diagrams of the ferroelectric antiferromagnet TbMnO is presented for the temperature region where the rare-earth subsystem is paramagnetic. It is shown that the behavior of the electric polarization in magnetic fields of different directions cannot ... [Low Temp. Phys. 34, 422 (2008)] published Mon Jun 30, 2008.
Theory of stochastic saturation of ferromagnetic resonance
A. I. Ugulava, Z. Z. Toklikishvili, and L. L. Chotorlishvili
One of the main models used to study problems of ferromagnetic resonance is the LandauLifshitz phenomenological model. According to this model, the dynamics of the magnetization in a ferromagnet is described by a nonlinear LandauLifshitz equation. Because of the nonlinearity of this equation the phy ... [Low Temp. Phys. 34, 418 (2008)] published Mon Jun 30, 2008.
Analysis of the pseudogap-related structure in the tunnel spectra of superconducting Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub 8 + delta] revealed by break-junction technique
T. Ekino, A. M. Gabovich, and A. I. Voitenko
The tunnel conductance G(V) for break junctions made of as-grown single-crystal BiSrCaCuO samples with T[approximate]8689 K is measured, and clear-cut diphump structures are found in the range of bias voltage V=80120 mV. A theory of tunneling in symmetric junctions between inhomogeneous charge-den ... [Low Temp. Phys. 34, 409 (2008)] published Mon Jun 30, 2008.
Paramagnetic hyperfine splitting in the [sup 151]Eu M[o-umlaut]ssbauer spectra of CaF[sub 2]:Eu[sup 2+]
J. Selling, B. Bielemeier, G. Wortmann, J. A. Johnson, E. E. Alp et al.
Eu Mossbauer spectra in zero magnetic field of highly dilute (0.1 mol%) Eu ions in CaF showed an almost temperature-independent asymmetrically split pattern, arising from the paramagnetic hyperfine interaction AS.I in a cubic crystal field with slow electron spin relaxation; in a small external magn ... [Phys. Rev. B 77, 224442 (2008)] published Mon Jun 30, 2008.
Correlation between ferroelectric polarization and sense of helical spin order in multiferroic MnWO[sub 4]
Hajime Sagayama, Kouji Taniguchi, Nobuyuki Abe, Taka-hisa Arima, Minoru Soda et al.
We report a polarized-neutron-diffraction study on a single crystal sample of MnWO, wherein the ferroelectricity and spiral magnetic order coexist. The direction of electric polarization controls the sense of helix that can be detected from the difference in intensities of magnetic satellites for pa ... [Phys. Rev. B 77, 220407 (2008)] published Mon Jun 30, 2008.
Phonon and crystal field excitations in geometrically frustrated rare earth titanates
T. T. A. Lummen, I. P. Handayani, M. C. Donker, D. Fausti, G. Dhalenne et al.
The phonon and crystal field excitations in several rare earth titanate pyrochlores are investigated. Magnetic measurements on single crystals of GdTiO, TbTiO, DyTiO, and HoTiO are used for characterization, while Raman spectroscopy and terahertz time domain spectroscopy are employed to probe the ex ... [Phys. Rev. B 77, 214310 (2008)] published Mon Jun 30, 2008.
Modulations of orders around a magnetic impurity in a d-wave superconductor
Xian-Jun Zuo, Jin An, and Chang-De Gong
In this Brief Report we study the effects of a magnetic impurity embedded in a d-wave superconductor based on the ttJV model by self-consistently solving the Bogoliubovde Gennes equations. It is found that with the variation of scattering strength, the orders around the impurity exhibit rich and int ... [Phys. Rev. B 77, 212508 (2008)] published Mon Jun 30, 2008.
One-gap scenario to explain Raman scattering in a d-wave superconductor
A. V. Chubukov and M. R. Norman
Recent Raman scattering data in B and B geometries in the superconducting state of underdoped cuprates were interpreted as evidence for two distinct energy gaps. We argue that these data can be equally well explained within a one-gap scenario if final-state interactions are taken into account. In pa ... [Phys. Rev. B 77, 214529 (2008)] published Mon Jun 30, 2008.
Quasi-intrinsic magnetoelectric coupling in multiferroic nanocomposite thin films
Jung H. Park, Hyun H. Shin, and Hyun M. Jang
Intrinsic tendency of magnetoelectric (ME) coupling in a given multiferroic system is difficult to experimentally substantiate because it represents the degree of coupling between polarization and magnetization vectors in the absence of any probing field. To assess the degree of this intrinsic coupl ... [Phys. Rev. B 77, 212409 (2008)] published Mon Jun 30, 2008.
Edge state magnetism of single layer graphene nanostructures
Somnath Bhowmick and Vijay B. Shenoy
We study edge state magnetism in graphene nanostructures using a mean field theory of the Hubbard model. We investigate how the magnetism of the zigzag edges of graphene is affected by the presence of other types of terminating edges and defects. By a detailed study of both regular shapes, such as p ... [J. Chem. Phys. 128, 244717 (2008)] published Mon Jun 30, 2008.
Giant microwave tunability in FeGaB/lead magnesium niobate-lead titanate multiferroic composites
J. Lou, D. Reed, C. Pettiford, M. Liu, P. Han et al.
Giant magnetoelectric coupling at both microwave frequencies and dc was observed in an FeGaB/lead magnesium niobate-lead titanate microwave multiferroic composite. A record high microwave frequency tunability of Deltaf=900 MHz or Deltaf/f=58% was demonstrated with the change of an external electric ... [Appl. Phys. Lett. 92, 262502 (2008)] published Mon Jun 30, 2008.
Shear-strain-induced low symmetry phase and domain ordering in epitaxial La[sub 0.7]Sr[sub 0.3]MnO[sub 3] thin films
S. W. Jin, G. Y. Gao, Z. Huang, Z. Z. Yin, X. Zheng et al.
The domain structure in epitaxial LaSrMnO films grown on (LaAlO)(SrAlTaO)(001) substrates has been investigated by x-ray reciprocal space maps on (003), (103), ([overline 1]03), (013), and (0[overline 1]3) reflections in the high-resolution scattering zone containing the c axis, and the transmission ... [Appl. Phys. Lett. 92, 261901 (2008)] published Mon Jun 30, 2008.
Extrinsic origin of ferromagnetism in single crystalline LaAlO[sub 3] substrates and oxide films
F. Golmar, A. M. Mudarra Navarro, C. E. Rodriguez Torres, F. H. Sanchez, F. D. Saccone et al.
Commercial LaAlO substrates were thermally cycled simulating a procedure similar to those followed during TiO and SnO dilute magnetic semiconductors' film pulsed laser deposition. Ferromagneticlike behavior was found in some substrates, in which metallic iron impurities were detected by x-ray photoe ... [Appl. Phys. Lett. 92, 262503 (2008)] published Mon Jun 30, 2008.
Conversion electron M[o-umlaut]ssbauer spectroscopy of epitaxial Co[sub 2]Cr[sub 0.6]Fe[sub 0.4]Al thin films
Vadim Ksenofontov, Christian Herbort, Martin Jourdan, and Claudia Felser
Heusler half-metals are promising for spintronic applications. Epitaxial thin films of the exemplar compound CoCrFeAl (CCFA) were investigated using conversion electron Mossbauer spectroscopy to clarify the factors influencing the spin polarization. CCFA films were deposited by rf magnetron sputteri ... [Appl. Phys. Lett. 92, 262501 (2008)] published Mon Jun 30, 2008.