Thermodynamics of the 3D Hubbard model on approach to the Neel transition

TL;DR

This paper investigates the thermodynamic behavior of the 3D Hubbard model near the Neel transition using cluster dynamical mean-field theory, providing insights relevant for cold-gas experiments and magnetic ordering.

Contribution

It presents detailed thermodynamic calculations of the 3D Hubbard model near the Neel transition, including effects of trapping potentials, which is novel for connecting theory with cold-atom experiments.

Findings

An entropy per particle of approximately 0.65 is sufficient for Neel ordering in trapped systems.

Nearest-neighbor spin correlations indicate precursors to antiferromagnetism.

The study extends understanding of thermodynamics close to magnetic phase transitions.

Abstract

We study the thermodynamic properties of the 3D Hubbard model for temperatures down to the Neel temperature using cluster dynamical mean-field theory. In particular we calculate the energy, entropy, density, double occupancy and nearest-neighbor spin correlations as a function of chemical potential, temperature and repulsion strength. To make contact with cold-gas experiments, we also compute properties of the system subject to an external trap in the local density approximation. We find that an entropy per particle $S/N \approx 0.65(6)$ at $U/t=8$ is sufficient to achieve a Neel state in the center of the trap, substantially higher than the entropy required in a homogeneous system. Precursors to antiferromagnetism can clearly be observed in nearest-neighbor spin correlators.