Nonuniversal Equation of State of the Two-Dimensional Bose Gas
Authors: Salasnich L.
Autors Affiliation: Dipartimento di Fisica e Astronomia “Galileo Galilei,” Università di Padova, Via Marzolo 8, 35131 Padova, Italy,
Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia (CNISM), Unità di Padova,Via Marzolo 8, 35131 Padova, Italy and Istituto Nazionale di Ottica (INO) del Consiglio Nazionale delle Ricerche (CNR), Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy
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 (13) Pages from: 130402-1 to: 130402-5
KeyWords: quantum field theory; bose-einstein condensation;