SearcharxivSearch

arXiv subjects

Gerhard Mueller

Publications and source records attributed to Gerhard Mueller.

2 recordsLinked to original sources

Thermodynamics of statistically interacting quantum gas in D dimensions

We present the exact thermodynamics (isochores, isotherms, isobars, response functions) of a statistically interacting quantum gas in D dimensions. The results in D=1 are those of the thermodynamic Bethe ansatz for the nonlinear Schroedinger model, a gas with repulsive two-body contact potential. In all dimensions the ideal boson and fermion gases are recovered in the weak-coupling and strong-coupling limits, respectively. For all nonzero couplings ideal fermion gas behavior emerges for D>>1 and, in the limit D->infinity, a phase transition occurs at T>0. Significant deviations from ideal quantum gas behavior are found for intermediate coupling and finite D.

cond-mat.stat-mech

Transition rates via Bethe ansatz for the spin-1/2 planar XXZ antiferromagnet

A novel determinantal representation for matrix elements of local spin operators between Bethe wave functions of the one-dimensional s=1/2 XXZ model is used to calculate transition rates for dynamic spin structure factors in the planar regime. In a first application, high-precision numerical data are presented for lineshapes and band edge singularities of the in-plane (xx) two-spinon dynamic spin structure factor.

cond-mat.str-el