Nonuniversal Equation of State of the Two-Dimensional Bose Gas
Authors: Salasnich L.
Autors Affiliation: Università di Padova e INO-CNR
Abstract: For a dilute two-dimensional Bose gas the universal equation of state has a logarithmic dependence on the s-wave scattering length. Here we derive nonuniversal corrections to this equation of state, taking account of finite-range effects of the interatomic potential. Our beyond-mean-field analytical results are obtained performing dimensional regularization of divergent zero-point quantum fluctuations within the finite-temperature formalism of functional integration. In particular, we find that in the grand canonical ensemble the pressure has a nonpolynomial dependence on the finite- range parameter and it is a highly nontrivial function of chemical potential and temperature.
Journal/Review: PHYSICAL REVIEW LETTERS
Volume: 118 Pages from: 130402 to: 130402
KeyWords: quantum field theory; bose-einstein condensation;