MAGNETIZATION CURVES OF QUASI-ONE-DIMENSIONAL HALDANE SYSTEMS

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3339-3342
Author(s):  
A. KAWAGUCHI ◽  
A. KOGA ◽  
N. KAWAKAMI ◽  
K. OKUNISHI
Keyword(s):  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Group Method ◽  
Density Matrix Renormalization Group ◽  
One Dimensional ◽  
Density Matrix Renormalization ◽  
Antiferromagnetic Correlation ◽  
Bond Alternation ◽  
Theoretical Results

We study the magnetization process of a quasi-one-dimensional S=1 antiferromagnet with bond alternation by using the density matrix renormalization group method combined with interchain mean-field approximation. Particularly, we discuss how the interchain couplings affect the magnetization curve around a plateau structure in both of the Haldane phase and the dimer phase. It is shown that the antiferromagnetic correlation induced by the interchain couplings reduces the region of the plateau significantly, which will play an important role when the theoretical results are compared with actual measurements of the magnetization.

The gas-liquid surface of the penetrable sphere model. II

1978 ◽  
Vol 358 (1694) ◽  
pp. 267-280 ◽  
Keyword(s):  
Surface Tension ◽  
Correlation Function ◽  
Liquid Surface ◽  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Intermolecular Potential ◽  
Direct Correlation Function ◽  
Sphere Model ◽  
One Dimensional

The direct correlation function between two points in the gas-liquid surface of the penetrable sphere model is obtained in a mean-field approximation. This function is used to show explicitly that three apparently different ways of calculating the surface tension all lead to the same result. They are (1) from the virial of the intermolecular potential, (2) from the direct correlation function, and (3) from the energy density. The equality of (1) and (2) is shown analytically at all temperatures 0 < T < T c where T c is the critical temperature; the equality of (2) and (3) is shown analytically for T ≈ T c , and by numerical integration at lower temperatures. The equality of (2) and (3) is shown analytically at all temperatures for a one-dimensional potential.

Stochastic Properties of a One-Dimensional Discrete Ginzburg-Landau Field

1981 ◽  
Vol 36 (1) ◽  
pp. 1-9
Author(s):  
M. Jaspers ◽  
W. Schattke
Keyword(s):  
Mean Field ◽  
Planck Equation ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Ginzburg Landau ◽  
Mean Values ◽  
One Dimensional ◽  
Slowing Down ◽  
Set Up ◽  
Stochastic Properties

Starting from a master equation for a discrete order parameter a dynamical model is set up via mean-field approximation in the Fokker-Planck equation. The time evolution of some mean values is calculated numerically, showing two transitions with characteristic slowing down of the relaxation time

COLLAPSE OF K-Rb FERMI-BOSE MIXTURES IN OPTICAL LATTICES

2006 ◽  
Vol 20 (30n31) ◽  
pp. 5199-5203
Author(s):  
D. M. JEZEK ◽  
H. M. CATALDO
Keyword(s):  
Low Temperature ◽  
Optical Lattice ◽  
Optical Lattices ◽  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
One Dimensional ◽  
Different Types ◽  
The Mean ◽  
Number Of Particles

We study a confined mixture of Rb and K atoms in a one dimensional optical lattice, at low temperature, in the quanta1 degeneracy regime. This mixture exhibits an attractive boson-fermion interaction, and thus above certain values of the number of particles the mixture collapses. We investigate, in the mean-field approximation, the curve for which this phenomenon occurs, in the space of number of particles of both species. This is done for different types of optical lattices.

FRÖHLICH'S ONE-DIMENSIONAL SUPERCONDUCTOR WITH PARA-FERMI STATISTICS

1994 ◽  
Vol 08 (19) ◽  
pp. 1195-1200 ◽  
Author(s):  
V. L. SAFONOV ◽  
A. V. ROZHKOV
Keyword(s):  
Density Wave ◽  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Wave State ◽  
One Dimensional ◽  
Fermi Statistics ◽  
The Mean ◽  
A Charge ◽  
Dimensional Crystal

The hypothesis that conduction electrons in a one-dimensional crystal obey para-Fermi statistics is discussed. Thermal properties of Fröhlich's model in the mean-field approximation are calculated within the framework of this hypothesis. It is shown that the temperature of the phase transition to a charge density wave state is greater in a system with parastatistics.

scholarly journals Impurities in a one-dimensional Bose gas: the flow equation approach

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fabian Brauneis ◽  
Hans-Werner Hammer ◽  
Mikhail Lemeshko ◽  
Artem Volosniev
Keyword(s):  
Mean Field ◽  
Interaction Strength ◽  
Field Approximation ◽  
Flow Equation ◽  
Mean Field Approximation ◽  
Bose Gases ◽  
One Dimensional ◽  
Flow Equations ◽  
Impurity Interaction ◽  
The Mean

A few years ago, flow equations were introduced as a technique for calculating the ground-state energies of cold Bose gases with and without impurities[1,2]. In this paper, we extend this approach to compute observables other than the energy. As an example, we calculate the densities, and phase fluctuations of one-dimensional Bose gases with one and two impurities. For a single mobile impurity, we use flow equations to validate the mean-field results obtained upon the Lee-Low-Pines transformation. We show that the mean-field approximation is accurate for all values of the boson-impurity interaction strength as long as the phase coherence length is much larger than the healing length of the condensate. For two static impurities, we calculate impurity-impurity interactions induced by the Bose gas. We find that leading order perturbation theory fails when boson-impurity interactions are stronger than boson-boson interactions. The mean-field approximation reproduces the flow equation results for all values of the boson-impurity interaction strength as long as boson-boson interactions are weak.

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