Skip to content

Condensed Matter papers — page 172

cond-matBrowse archive

Fate of a Bose-Einstein condensate with attractive interaction
We calculate the decay amplitude of a harmonically trapped Bose-Einstein condensate with attractive interaction via the Feynman path integral. We find that when the number of particles is less than a…
Masahito Ueda, Kerson HuangJul 27, 1998
Learn
Kinetic Monte Carlo simulations of the growth of polymer crystals
Based upon kinetic Monte Carlo simulations of crystallization in a simple polymer model we present a new picture of the mechanism by which the thickness of lamellar polymer crystals is constrained to…
Jonathan Doye, Daan FrenkelJul 27, 1998
Learn
Broad Histogram Relation Is Exact
The Broad Histogram is a method designed to calculate the energy degeneracy g(E) from microcanonical averages of certain macroscopic quantities Nup and Ndn. These particular quantities are defined…
Paulo Murilo Castro de OliveiraJul 27, 1998
Learn
Detection of vorticity in Bose-Einstein condensed gases by matter-wave interference
A phase-slip in the fringes of an interference pattern is an unmistakable characteristic of vorticity. We show dramatic two-dimensional simulations of interference between expanding condensate clouds…
Eric L. Bolda, Dan F. WallsJul 27, 1998
Learn
Structural Transitions and Global Minima of Sodium Chloride Clusters
In recent experiments on sodium chloride clusters structural transitions between nanocrystals with different cuboidal shapes were detected. Here we determine reaction pathways between the low energy…
Jonathan Doye, David WalesJul 27, 1998
Learn
Escape rate of the nanospin system in a magnetic field: the first-order phase transition within quantum regime
We have investigated the escape rate of the nanospin particle with a magnetic field applied along the easy axis. The model studied here is described by the Hamiltonian $ H = K1 Sz2…
Chang Soo Park, Sahng-Kyoon Yoo, D. K. Park et al.Jul 26, 1998
Learn
An Exactly Solvable Model of Generalized Spin Ladder
A detailed study of an S=12 spin ladder model is given. The ladder consists of plaquettes formed by nearest neighbor rungs with all possible SU(2)-invariant interactions. For properly chosen…
S. Albeverio, S. M. Fei, Y. P. WangJul 25, 1998
Learn
Electrical Conductivity of Fermi Liquids. II. Quasiparticle Transport
We develop a general theory of Fermi liquids to discuss the Kadowaki-Woods relation A γ2. We derive a formula for the ratio A/γ2 which is expressed as a product of two dimensionless…
Takuya OkabeJul 25, 1998
Learn
Electrical Conductivity of Fermi Liquids. I. Many-body Effect on the Drude Weight
On the basis of the Fermi liquid theory, we investigate the many-body effect on the Drude weight. In a lattice system, the Drude weight D is modified by electron-electron interaction due to Umklapp…
Takuya OkabeJul 25, 1998
Learn
Density-functional study of hydrogen chemisorption on vicinal Si(001) surfaces
Relaxed atomic geometries and chemisorption energies have been calculated for the dissociative adsorption of molecular hydrogen on vicinal Si(001) surfaces. We employ density-functional theory,…
E. Pehlke, P. KratzerJul 24, 1998
Learn
Capture of carriers to screened charged centres and low temperature shallow impurity electric field break down in semiconductors
Free carrier capture by a screened Coulomb potential in semiconductors are considered. It is established that with decreasing screening radius the capture cross section decreases drastically, and it…
O. Z. AlekperovJul 24, 1998
Learn
n-GaAs quality diagnose from shallow impurities photoelectric spectroscopy line shapes dependence on electric field
It is established experimentally that the low temperature photoelectric spectra line width of shallow impurities depends not only on charged impurity concentration Ni=2KNA and degree of samples…
O. Z. AlekperovJul 24, 1998
Learn
Multi-connected Momentum Distribution and Fermion Condensation
The structure of the ground state beyond the instability point of the quasiparticle system with Fermi-step momentum distribution is studied within the model of a Fermi liquid with a strong repulsive…
M. V. Zverev, M. BaldoJul 24, 1998
Learn
Ward Identities for Interacting Electronic Systems
A Ward-Takahashi identity, as a consequence of gauge invariance and in a form that relates self-energy to the two-particle Bethe-Salpeter scattering kernel, was first derived by Vollhardt and Wölfle…
H. T. Nieh, Ping Sheng, Xiao-Bing WangJul 23, 1998
Learn
Avalanche mixing of granular solids in a rotating 2D drum and discrete mapping
Evolution of mixing of granular solids in a slowly rotated 2D drum is considered as a discrete mapping. The rotation is around the axis of the upright drum which is filled partially, and the mixing…
S. N. DorogovtsevJul 22, 1998
Learn
Mesoscopic Physics and the Fundamentals of Quantum Mechanics
We start by reviewing some interesting results in mesoscopic physics illustrating nontrivial insights on Quantum Mechanics. We then review the general principles of dephasing (sometimes called…
Yoseph ImryJul 22, 1998
Learn
Cantori and dynamical localization in the Bunimovich Stadium
Classical and quantum properties of the Bunimovich stadium in the diffusive regime are reviewed. In particular, the quantum properties are directly investigated using an approximate quantum map.…
Fausto Borgonovi, Paolo Conti, Daniela Rebuzzi et al.Jul 22, 1998
Learn
Simulation of a non-invasive charge detector for quantum cellular automata
Information in a Quantum Cellular Automata architecture is encoded in the polarizazion state of a cell, i.e., in the occupation numbers of the quantum dots of which the cell is made up. Non-invasive…
G. Iannaccone, C. Ungarelli, M. Macucci et al.Jul 22, 1998
Learn
Current partition: Nonequilibrium Green's function Approach
We present a solution to the problem of AC current partition in a multi-probe mesoscopic conductor within the nonequilibrium Green's function formalism. This allows the derivation of dynamic…
Baigeng Wang, Jian Wang, Hong GuoJul 22, 1998
Learn
A Wannier-function-based ab initio Hartree-Fock study of polyethylene
In the present letter, we report the extension of our Wannier-function-based ab initio Hartree-Fock approach---meant originally for three-dimensional crystalline insulators---to deal with…
Alok Shukla, Michael Dolg, Hermann StollJul 21, 1998
Learn
Alternating Spin and Orbital Dimerization in Strong-coupling Two-band Models
We study a one-dimensional Hamiltonian consisting of coupled SU(2) spin and orbital degrees of freedom. Using the density matrix renormalization group, we calculate the phase-diagram and the ground…
Swapan K. Pati, Rajiv R. P. Singh, Daniel I. KhomskiiJul 20, 1998
Learn
Optical Conductivity in the Copper Oxide Materials
The frequency- and temperature-dependent optical conductivity of the copper oxide materials in the underdoped and optimal doped regimes are studied within the t-J model. The conductivity spectrum…
Zhongbing Huang, Shiping FengJul 19, 1998
Learn
Vortex stabilization in Bose-Einstein condensate of alkali atom gas
A quantized vortex in the Bose-Einstein condensation (BEC), which is known to be unstable intrinsically, is demonstrated theoretically to be stabilized by the finite temperature effect. The…
Tomoya Isoshima, Kazushige MachidaJul 17, 1998
Learn
Interfacial Structural Changes and Singularities in Non-Planar Geometries
We consider phase coexistence and criticality in a thin-film Ising magnet with opposing surface fields and non-planar (corrugated) walls. We show that the loss of translational invariance has a…
C. Rascon, A. O. ParryJul 17, 1998
Learn
Transition from Sub-Poissonian to Super-Poissonian Shot Noise in Resonant Quantum Wells
We investigate the transition from sub-Poissonian to super-Poissonian values of the zero-temperature shot noise power of a resonant double barrier of macroscopic cross-section. This transition occurs…
Ya. M. Blanter, M. ButtikerJul 17, 1998
Learn
← PreviousPage 172Next →