Superfluidity of Mesoscopic Bose Gases under Varying Confinements

Abstract

The superfluid fraction $N_s/N$ of 27 bosons under varying confinement is investigated at finite temperature using well-known properties of the harmonic oscillator and the microscopic path integral Monte Carlo method. We find that $N_s/N$ (i) is essentially independent of the interaction strength for all temperatures considered, (ii) changes profoundly as the effective dimensionality is varied from three to one dimensional, (iii) is approximately equal to the condensate fraction $N_0/N$ for spherical Bose gases, and (iv) deviates dramatically from $N_0/N$ for highly elongated Bose gases.