Raman Amplification of Matter WavesWe demonstrate a Raman amplifier for matter-waves, where the amplified atoms and the gain medium are in two different hyperfine states. This amplifier is based on a novel form of superradiance that…Dominik Schneble, Gretchen K. Campbell, Erik W. Streed et al.·Nov 6, 2003SaveLearn
Alloy effects in GaInN/GaN heterostructuresWe show that the large band offsets between GaN and InN and the heavy carrier effective masses preclude the use of the Virtual Crystal Approximation to describe the electronic structure of…Duc Phuong Nguyen, Nicolas Regnault, Robson Ferreira et al.·Nov 6, 2003SaveLearn
Transverse negative magnetoresistance of 2D structures in the presence of strong in-plane magnetic field: weak localization as a probe of interface roughnessThe interference induced transverse negative magnetoresistance of GaAs/InGaAs/GaAs quantum well heterostructures has been studied in the presence of strong in-plane magnetic field. It is shown that…G. M. Minkov, O. E. Rut, A. V. Germanenko et al.·Nov 6, 2003SaveLearn
Modelling of Optical Detection of Spin-Polarized Carrier Injection into Light-Emitting DevicesWe investigate the emission of multimodal polarized light from Light Emitting Devices due to spin-aligned carriers injection. The results are derived through operator Langevin equations, which…M. C. de Oliveira, He Bi Sun·Nov 5, 2003SaveLearn
Functional Complexity Measure for NetworksWe propose a complexity measure which addresses the functional flexibility of networks. It is conjectured that the functional flexibility is reflected in the topological diversity of the assigned…Hildegard Meyer-Ortmanns·Nov 5, 2003SaveLearn
Charge density plateaux and insulating phases in the t-J model with ladder geometryWe discuss the occurrence and the stability of charge density plateaux in ladder-like t-J systems (at zero magnetization M=0) for the cases of 2- and 3-leg ladders. Starting from isolated rungs at…A. Fledderjohann, A. Langari, K. -H. Muetter·Nov 5, 2003SaveLearn
On-surface and Subsurface Adsorption of Oxygen on Stepped Ag(210) and Ag(410) SurfacesThe adsorption of atomic oxygen and its inclusion into subsurface sites on Ag(210) and Ag(410) surfaces have been investigated using density functional theory. We find that--in the absence of adatoms…A. Kokalj, N. Bonini, A. Dal Corso et al.·Nov 5, 2003SaveLearn
"Turbulent" electrical transport in Copper powdersCompressed copper powder has a very large electrical resistance (1MOhm), due to the oxide layer on grains (100 micro m). We observe that its voltage-current U-I characteristics are nonlinear, and…Eric Falcon, Bernard Castaing, Claude Laroche·Nov 5, 2003SaveLearn
Vacuum-field Rabi oscillations in atomically doped carbon nanotubesWe report a strictly non-exponential spontaneous decay dynamics of an excited two-level atom placed inside or at different distances outside a carbon nanotube. This is the result of strong…I. V. Bondarev, G. Ya. Slepyan, S. A. Maksimenko et al.·Nov 4, 2003SaveLearn
On the Form Factor for the Unitary GroupWe study the combinatorics of the contributions to the form factor of the group U(N) in the large N limit. This relates to questions about semiclassical contributions to the form factor of quantum…Mirko Degli Esposti, Andreas Knauf·Nov 4, 2003SaveLearn
Dark Matter-Wave Solitons in Optical LatticesWe analyze the Floquet-Bloch matter-wave spectrum of Bose-Einstein condensates loaded into single-periodic optical lattices and double-periodic superlattices. In the framework of the Gross-Pitaevskii…Pearl J. Y. Louis, Elena A. Ostrovskaya, Yuri S. Kivshar·Nov 4, 2003SaveLearn
Dissipationless Spin Current in Anisotropic p-Doped SemiconductorsRecently, dissipationless spin current has been predicted for the p-doped semiconductors with spin-orbit coupling. Here we investigate the effect of spherical symmetry breaking on the dissipationless…Bogdan A. Bernevig, JiangPing Hu, Eran Mukamel et al.·Nov 3, 2003SaveLearn
Hall effect in cobalt-doped TiO2-δWe report Hall effect measurements on thin films of cobalt-doped TiO2-δ. Films with low carrier concentrations (1018 - 1019) yield a linear behavior in the Hall data while those having…J. S. Higgins, S. R. Shinde, S. B. Ogale et al.·Nov 3, 2003SaveLearn
Energy levels in polarization superlattices: a comparison of continuum strain modelsA theoretical model for the energy levels in polarization superlattices is presented. The model includes the effect of strain on the local polarization-induced electric fields and the subsequent…B. Jogai, J. D. Albrecht, E. Pan·Nov 3, 2003SaveLearn
Angular distribution of photoluminescence as a probe of Bose Condensation of trapped excitonsRecent experiments on two-dimensional exciton systems have shown the excitons collect in shallow in-plane traps. We find that Bose condensation in a trap results in a dramatic change of the exciton…Jonathan Keeling, L. S. Levitov, P. B. Littlewood·Nov 3, 2003SaveLearn
Temperature Dependence of the UCN Loss RateWe report about the first results obtained with our Ultra High Vacuum cryostat recently commissioned at HMI to study Ultra Cold Neutrons(UCN) loss rate under low temperatures(down to 4K) and well…S. Arzumanov, J. Butterworth, R. Golub et al.·Nov 3, 2003SaveLearn
Coherence of trapped one-dimensional (quasi-)condensates and acontinuous atom lasers in waveguidesWe present a model for a continuous atom laser in a one-dimensional waveguide. The beam is formed by continuous Raman outcoupling of a trapped one-dimensional (quasi-)condensate, which is created by…N. P. Proukakis·Oct 31, 2003SaveLearn
Dynamical instability of a dark soliton in a quasi-one-dimensional Bose-Einstein condensate perturbed by an optical latticeThe motion of a dark soliton is investigated in a one-dimensional dilute Bose-Einstein condensate confined in a harmonic trap and an optical lattice. The harmonic trap induces a dynamical instability…N. G. Parker, N. P. Proukakis, C. F. Barenghi et al.·Oct 31, 2003SaveLearn
Unconventional magnetism in all-carbon nanofoamWe report production of nanostructured carbon foam by a high-repetition-rate, high-power laser ablation of glassy carbon in Ar atmosphere. A combination of characterization techniques revealed that…A. V. Rode, E. G. Gamaly, A. G. Christy et al.·Oct 31, 2003SaveLearn
Quantum Monte Carlo study of quasi-one-dimensional Bose gasesWe study the behavior of quasi-one-dimensional (quasi-1d) Bose gases by Monte Carlo techniques, i.e., by the variational Monte Carlo, the diffusion Monte Carlo, and the fixed-node diffusion Monte…G. E. Astrakharchik, D. Blume, S. Giorgini et al.·Oct 31, 2003SaveLearn
Dynamical Mechanisms in Multi-agent Systems: Minority GamesWe consider a version of large population games whose agents compete for resources using strategies with adaptable preferences. Diversity among the agents reduces their maladpative behavior. We find…K. Y. Michael Wong, S. W. Lim, Zhuo Gao·Oct 31, 2003SaveLearn
Self-consistent fragmented excited states of trapped condensatesSelf-consistent excited states of condensates are solutions of the Gross-Pitaevskii (GP) equation and have been amply discussed in the literature and related to experiments. By introducing a more…L. S. Cederbaum, A. I. Streltsov·Oct 29, 2003SaveLearn
Best mean-field for condensatesThe Gross-Pitaevskii equation assumes that all (identical) bosons of a condensate reside in a single one-particle function. Here, we raise the question whether it always provides the best mean-field…L. S. Cederbaum, A. I. Streltsov·Oct 29, 2003SaveLearn
Correlations between pressure and bandwidth effects in metal-insulator transitions in manganitesThe effect of pressure on the metal-insulator transition in manganites with a broad range of bandwidths is investigated. A critical pressure is found at which the metal-insulator transition…Congwu Cui, Trevor A. Tyson·Oct 29, 2003SaveLearn
All-electron self-consistent GW approximation: Application to Si, MnO, and NiOWe present a new kind self-consistent GW approximation (scGW) based on the all-electron, full-potential LMTO method. By iterating the eigenfunctions of the GW Hamiltonian, self-consistency in both…Sergey V. Faleev, Mark van Schilfgaarde, Takao Kotani·Oct 29, 2003SaveLearn