arXiv subjects

V. S. Kapitonov

Publications and source records attributed to V. S. Kapitonov.

3 recordsLinked to original sources

arXiv1999

Finite-temperature correlations in the trapped Bose gas

Previous functional integral methods for translationally invariant systems have been extended to the case of a confining trap potential. Essentially all finite-temperature properties of the repulsive Bose gas in a paraboloidal trap can be determined this way. New analytical results reported here are for the finite-temperature two-point correlation functions below the critical temperatures in d=3,2 and 1 dimensions. Only for d=3 are correlations both long range and coherent - at long range consistent with the existence of a coherent state of the condensate in the trap. The two-dimensional condensate is marginally stable in the sense that correlations decay by a power law.

cond-mat.stat-mech↗

arXiv1997

Equal-time temperature correlators of the one-dimensional Heisenberg XY chain

Representations as determinants of $M\times M$ dimensional matrices are obtained for equal-time temperature correlators of the anisotropic Heisenberg XY chain. These representations are simple deformations of the answers for the isotropic XX0 chain. In the thermodynamic limit, the correlators are expressed in terms of the Fredholm determinants of linear integral operators.

solv-int↗

arXiv1995

Exchange statistics in 1D: from the viewpoint of exact solution

We show that the exchange statistics have consequences in 1D systems with compact topology, contrary to the common opinion that exchange statistics is arbitrary in 1D. As examples of non-trivial statistical behavior we exactly calculate the partition function and correlators for systems of free q-particles on compactified chains using functional integral techniques and the supersymmetric trick. In particular we consider a spin 1/2 XY-chain with periodic boundary conditions that corresponds to the case of q=-1.

hep-th↗