Optical response and spin relaxation in semiconductor systems under excitation with arbitrary polarizationThe equations-of-motion for the density matrix are derived in a multiband model to describe the response of semiconductors (bulk or quantum well structures) under optical excitation with arbitrary…U. Rössler·Sep 17, 2002SaveLearn
Nuclear resonant scattering of Synchrotron radiation from nuclei in the Browninan motionThe time evolution of the coherent forward scattering of Synchrotron radiation for resonant nuclei in Brownian motion is studied . Apart from target thickness, the appearance of dynamical beats also…Ashok Razdan·Sep 17, 2002SaveLearn
Negative high-frequency differential conductivity in semiconductor superlatticesWe examine the high-frequency differential conductivity response properties of semiconductor superlattices having various miniband dispersion laws. Our analysis shows that the anharmonicity of Bloch…Yuriy A. Romanov, Lev G. Mourokh, Norman J. M. Horing·Sep 16, 2002SaveLearn
Effects of epitaxial strain on the growth mechanism of YBa2Cu3O7-x thin films in [YBa2Cu3O7-x / PrBa2Cu3O7-x] superlatticesWe report on the growth mechanism of YBa2Cu3O7-x (YBCO). Our study is based on the analysis of ultrathin, YBa2Cu3O7-x layers in c-axis oriented YBa2Cu3O7-x / PrBa2Cu3O7-x superlattices. We have found…M. Varela, W. Grogger, D. Arias et al.·Sep 16, 2002SaveLearn
Schroedinger equation for current carrying statesSchrödinger equation with given, a priori known current is formulated. A non-zero current density is maintained in the quantum system via a subsidiary condition imposed by vector, local…D. S. Kosov·Sep 15, 2002SaveLearn
Magnon-polaron and Spin-polaron Signatures in the Specific Heat and Electrical Resistivity of La0.6Y0.1Ca0.3MnO3 in Zero Magnetic Field, and the Effect of Mn-O-Mn Bond EnvironmentLa0.6Y0.1Ca0.3MnO3, an ABO3 perovskite manganite oxide, exhibits a non trivial behavior in the vicinity of the sharp peak found in the resistivity ρ as a function of temperature…M. Ausloos, L. Hubert, S. Dorbolo et al.·Sep 14, 2002SaveLearn
Generalized (m,k)-Zipf law for fractional Brownian motion-like time series with or without effect of an additional linear trendWe have translated fractional Brownian motion (FBM) signals into a text based on two ''letters'', as if the signal fluctuations correspond to a constant stepsize random walk. We have…Ph. Bronlet, M. Ausloos·Sep 13, 2002SaveLearn
Conservation laws in the quantum Hall Liouvillian theory and its generalizationsIt is known that the localization length scaling of noninteracting electrons near the quantum Hall plateau transition can be described in a theory of the bosonic density operators, with no reference…Joel E. Moore·Sep 12, 2002SaveLearn
Electron Spin Relaxation in a Semiconductor Quantum WellA fully microscopic theory of electron spin relaxation by the D'yakonov-Perel' type spin-orbit coupling is developed for a semiconductor quantum well with a magnetic field applied in the…Vadim I. Puller, Lev G. Mourokh, Norman J. M. Horing et al.·Sep 12, 2002SaveLearn
Avoided Phase Transitions and Glassy Dynamics In Geometrically Frustrated Systems and Non-Abelian TheoriesWe demonstrate that the application of any external uniform non-abelian gauge background, no matter how small, leads to a greatly enhanced degeneracy. This degeneracy is so large that even a…Zohar Nussinov·Sep 12, 2002SaveLearn
Finite-Size Scaling and Universality of the Thermal Resistivity of Liquid 4He near TλWe present measurements of the thermal resistivity ρ(t,P,L) near the superfluid transition of 4He at saturated vapor pressure and confined in cylindrical geometries with radii L=0.5 and 1.0…Daniel Murphy, Edgar Genio, Guenter Ahlers et al.·Sep 11, 2002SaveLearn
Current and Noise in a FM/quantum dot/FM SystemUsing the Keldysh nonequilibrium technique we calculate current, noise and Fano factor in a ferromagnetic(FM)-quantum dot-ferromagnetic(FM) system with Coulomb interaction and spin-flip scattering in…F. M. Souza, J. C. Egues, A. P. Jauho·Sep 11, 2002SaveLearn
Classical ground states of symmetrical Heisenberg spin systemsWe investigate the ground states of classical Heisenberg spin systems which have point group symmetry. Examples are the regular polygons (spin rings) and the seven quasi-regular polyhedra including…Heinz-Juergen Schmidt, Marshall Luban·Sep 11, 2002SaveLearn
New Evidence for Zero-Temperature Relaxation in a Spin-Polarized Fermi LiquidSpin-echo experiments are reported for 3He-4He solutions under extremely high B/T conditions, B=14.75 T and T >= 1.73 mK. The 3He concentration x3 was adjusted close to the value xc = 3.8% at which…H. Akimoto, D. Candela, J. S. Xia et al.·Sep 10, 2002SaveLearn
Effective Field Theory for Goldstone Bosons in Nonrelativistic SuperfluidsWe consider nonrelativistic superfluids where the global U(1)-symmetry is spontaneously broken. At sufficiently long wavelengths, the relevant degree of freedom is the massless Goldstone mode and we…Jens O. Andersen·Sep 10, 2002SaveLearn
Immigration, integration and ghetto formationWe study ghetto formation in a population with natives and immigrants in the framework of the two-dimensional Ising-model with Kawasaki-exchange dynamics. It is the phase structure of the Ising…Hildegard Meyer-Ortmanns·Sep 10, 2002SaveLearn
Decoherence and Relaxation of a Quantum Bit in the Presence of Rabi OscillationsDissipative dynamics of a quantum bit driven by a strong resonant field and interacting with a heat bath is investigated. We derive generalized Bloch equations and find modifications of the…Anatoly Yu. Smirnov·Sep 9, 2002SaveLearn
Controlling collapse in Bose-Einstein condensates by temporal modulation of the scattering lengthWe consider, by means of the variational approximation (VA) and direct numerical simulations of the Gross-Pitaevskii (GP) equation, the dynamics of 2D and 3D condensates with a scattering length…F. Kh. Abdullaev, J. G. Caputo, R. A. Kraenkel et al.·Sep 9, 2002SaveLearn
Coulomb singularity effects in tunnelling spectroscopy of individual impuritiesNon-equilibrium Coulomb effects in resonant tunnelling processes through deep impurity states are analyzed. It is shown that Coulomb vertex corrections to the tunnelling transfer amplitude lead to a…P. I. Arseyev, N. S. Maslova, V. I. Panov et al.·Sep 9, 2002SaveLearn
Optical response of two-dimensional electron fluids beyond the Kohn regime: strong non-parabolic confinement and intense laser lightWe investigate the linear and non-linear optical response of two-dimensional (2D) interacting electron fluids confined by a strong non-parabolic potential. We show that such fluids may exhibit…M. Santer, B. Mehlig, M. Moseler·Sep 6, 2002SaveLearn
Spin relaxation and antisymmetric exchange in n-doped III-V semiconductorRecently K. Kavokin [Phys. Rev. B 64, 075305 (2001)] suggested that the Dzyaloshinskii-Moriya interaction between localized electrons governs slow spin relaxation in n-doped GaAs in the regime…L. P. Gor'kov, P. L. Krotkov·Sep 5, 2002SaveLearn
Effective-action approach to a trapped Bose gasThe effective-action formalism is applied to a gas of bosons. The equations describing the condensate and the excitations are obtained using the loop expansion for the effective action. For a…Emil Lundh, Jorgen Rammer·Sep 5, 2002SaveLearn
Erratum: Low-dimensional Bose gases (PRA 66, 013615 (2002))We discuss some subtleties regarding the depletion of the condensate in homogeneous two and three-dimensional Bose at zero temperature. We find agreement with the results of Popov theory. Other…U. Al Khawaja, J. O. Andersen, N. P. Proukakis et al.·Sep 5, 2002SaveLearn
Application of Minimal Subtraction Renormalization to Crossover Behavior near the 3He Liquid-Vapor Critical PointParametric expressions are used to calculate the isothermal susceptibility, specific heat, order parameter, and correlation length along the critical isochore and coexistence curve from the…Fang Zhong, M. Barmatz, Inseob Hahn·Sep 5, 2002SaveLearn
Diversification and Gerneralized Tracking Errors For Correlated Non-Normal ReturnsThe probability distribution for the relative return of a portfolio constructed from a subset n of the assets from a benchmark, consisting of N assets whose returns are multivariate normal, is…Mark B. Wise, Vineer Bhansali·Sep 4, 2002SaveLearn