Effect of impurities on the transition temperature of a dilute dipolar trapped Bose gas

Abstract

By using a two-fluid model the effect of impurities on the transition temperature of a dipolar trapped Bose gas is investigated. By treating Gaussian spatial correlation for impurities from the interaction modified spectra of the system, the formula for the shift of the transition temperature is derived. The shift of the transition temperature contains essentially three contributions due to contact, dipole-dipole, and impurity interactions. Applying our results to dipolar Bose gases shows that the shift of the transition temperature due to impurities could be measured for an isotropic trap (dipole-dipole contribution is zero) and the Feshbach resonance technique (contact potential contribution is negligible).

Phase-dependent heat current of granular Josephson junction for different geometries

“…Based on the Meilikhov ś model, the granular critical current is obtained by averaging over all superconducting grains with random distribution function [36]. Previously we implemented this procedure to obtain the electrical current of granular s-wave [33] and d-wave [34] superconductors with different geometries. Now in this study, we consider a Josephson junction made by conventional superconducting grains.…”

“…Another protocol to enhance the transport properties becomes possible by applying different geometric frustration for the junction areas. The particular geometries used in junctions for studying the electrical transport [33,34] and thermal current [35] are rectangular, circular, and annular.…”

“…The aim of this paper is to study the phase-dependent heat current of the granular Josephson junction under the effect of a magnetic field control. Previously, we calculate the electric transport of granular s-wave [33] and dwave [34] superconducting systems in an applied magnetic field. To obtain the thermal current of the granular Josephson junction in analogy with the electric current, firstly we consider the heat current of the bulk superconducting system with different geometries [35].…”