We study the nonuniform potential effect in a quasi--two-dimensional (2D) Bose gas system at a finite temperature by numerically solving the projected Gross-Pitaevskii equation. The gradual emergence of superfluidity is confirmed by calculating the moment of inertia as the temperature decreases. Reflecting the nonuniformity of the system, the long-distance decay of a phase-correlation function is characterized by a local effective exponent, $\ensuremath{\eta}(r)$, which depends on the local superfluid density. This ``local-density approximation'' is endorsed by the 2D Gaussian field theory with the nonuniform coupling constant. Indeed, the effective exponent turns out to be close to $1/4$ at the boundary of the phase-coherent region.We study the nonuniform potential effect in a quasi--two-dimensional (2D) Bose gas system at a finite temperature by numerically solving the projected Gross-Pitaevskii equation. The gradual emergence of superfluidity is confirmed by calculating the moment of inertia as the temperature decreases. Reflecting the nonuniformity of the system, the long-distance decay of a phase-correlation function is characterized by a local effective exponent, $\ensuremath{\eta}(r)$, which depends on the local superfluid density. This ``local-density approximation'' is endorsed by the 2D Gaussian field theory with the nonuniform coupling constant. Indeed, the effective exponent turns out to be close to $1/4$ at the boundary of the phase-coherent region.

Physical Review AFeb 3, 20102 citations

Superfluidity of Two–Dimensional and One–Dimensional Systems

WORLD SCIENTIFIC eBooksNov 1, 20090 citations

Two-Body Correlations and the Superfluid Fraction for Nonuniform Systems

Wayne M. Saslow, Davide Emilio Galli, L. Reatto

arXiv:cond-mat/0612464Journal of Low Temperature PhysicsJul 11, 20075 citations

Quantum Field Theory Approach to Superfluidity

Eduardo C. Marino

Cambridge University Press eBooksOct 25, 20170 citations

On the theory of a Bose gas in a nonuniform field

S. I. Shevchenko

A new method of description of Bose systems in external fields is proposed. Equations derived on the basis of this method are the Bose analog of the Bogolyubov–De Gennes equations for Fermi systems with pairing. An exact solution of the equations is obtained for the case when a Bose system is in a field varying linearly with the coordinate. The possibility of propagation of previously unknown surface oscillations in a nonuniform field is predicted. The effect of the nonuniform field on the long-range order in two- and three-dimensional Bose systems is investigated.A new method of description of Bose systems in external fields is proposed. Equations derived on the basis of this method are the Bose analog of the Bogolyubov–De Gennes equations for Fermi systems with pairing. An exact solution of the equations is obtained for the case when a Bose system is in a field varying linearly with the coordinate. The possibility of propagation of previously unknown surface oscillations in a nonuniform field is predicted. The effect of the nonuniform field on the long-range order in two- and three-dimensional Bose systems is investigated.

Soviet Journal of Low Temperature PhysicsApr 1, 199214 citations

1/4

at the boundary of the phase-coherent region.