Chemical potential-induced effects on caloric properties of a Fermi-Hubbard dimer

Abstract

Chemical potential is one of the tunable properties of an optical lattice system when its temperature is varied. In this study, the effects of the chemical potential on the entropy and the heat capacity of a Fermi-Hubbard dimer immersed in a mean-field Fermi gas bath are calculated. Repulsive two-particle interactions are found to require lesser chemical potentials to observe a rapid increase in the entropy at low temperatures. Such phenomena signify quantum level crossings. Furthermore, half-filling of the optical dimer is unnecessary for such phenomena to occur.