Quantum Fluids in Thermodynamic Geometry

Abstract

In this work, the Thermodynamic Geometry (TG) of quantum fluids (QF) is analyzed. We present results for two models. The first one is a quantum hard-sphere fluid (QHS) whose Helmholtz free energy is obtained from Path Integrals Monte Carlo simulations (PIMC). It is found that due to quantum contributions in the thermodynamic potential, the anomaly found in TG for the classical hard-sphere fluid related to the sign of the scalar curvature, is now avoided in a considerable region of the thermodynamic space. The second model is a semi-classical square-well fluid (QSW), described by a quantum hard-sphere repulsive interaction coupled with a classical attractive square-well contribution. Behavior of the semi-classical curvature scalar as a function of the thermal de Broglie wavelength $\lambda_B$ is analyzed for several attractive-potential ranges, and description of the semi-classical R-Widom lines defined by the maxima of the curvature scalar, are also obtained and compared with classical results for different square-well ranges.Comment: 9 pages, 8 figure