Strong coupling effects on specific heat in the BCS-BEC crossover

Abstract

We theoretically investigate strong-coupling effects on specific heat at constant volume $C_{\mathrm{V}}$ in a superfluid Fermi gas with a tunable interaction associated with Feshbach resonance. Including fluctuations of the superfluid order parameter within the strong-coupling theory developed by Nozières and Schmitt-Rink, we calculate the temperature dependence of $C_{\mathrm{V}}$ at the unitarity limit in the superfluid phase. We show that, in the low temperature region, $T^3$-behavior is shown in the temperature dependence of $C_{\mathrm{V}}$. This result indicates that the low-lying excitations are dominated by the gapless Goldstone mode, associated with the phase fluctuations of the superfluid order parameter. Since the Goldstone mode is one of the most fundamental phenomena in the Fermionic superfluidity, our results are useful for further understanding how the pairing fluctuations affects physical properties in the BCS-BEC crossover physics below the superfluid transition temperature.

8 pages, 4 figures

References in corpus (5)

• Collective excitations of a degenerate gas at the BEC-BCS crossover
• Thermodynamics of the BCS-BEC crossover
• Equation of state of a superfluid Fermi gas in the BCS-BEC crossover
• Thermodynamic Measurements in a Strongly Interacting Fermi Gas
• Temperature of a trapped unitary Fermi gas at finite entropy