Normal-State Properties of a Unitary Bose–Fermi Mixture: A Combined Strong-Coupling Approach with Universal Thermodynamics

Abstract

JapanWe theoretically investigate normal-state properties of a unitary Bose-Fermi mixture. Including strong hetero-pairing fluctuations, we evaluate the Bose and Fermi chemical potential, internal energy, pressure, entropy, as well as specific heat at constant volume C V , within the framework of a combined strong-coupling theory with exact thermodynamic identities. We show that hetero-pairing fluctuations at the unitarity cause non-monotonic temperature dependence of C V , being qualitatively different from the monotonic behavior of this quantity in the weak-and strong-coupling limit. On the other hand, such an anomalous behavior is not seen in the other quantities. Our results indicate that the specific heat C V , which has recently become observable in cold atom physics, is a useful quantity for understanding strong-coupling aspects of this quantum system.

Second root of dilute Bose-Fermi mixtures

“…The present article deals with the dilute Bose-Fermi mixture with the tightly-bound dimers formed in dimensions between d = 2 and d = 4 at absolute zero. The previous studies in this context were mostly focused on the three-dimensional systems with the boson-fermion interaction fine-tuned to either narrow [23] or broad [24][25][26] Feshbach resonances. Nonetheless, there are some quantitative differences in physics of these two models, the general features of their properties are quite similar.…”