Estimate of the Phase Transition Line in the Infinite-dimensional Hubbard Model

TL;DR

This paper accurately maps the phase transition line in the infinite-dimensional Hubbard model using dynamical mean-field theory and quantum Monte Carlo, revealing how the transition approaches zero-temperature results.

Contribution

It introduces a systematic method to construct the first-order phase transition line in the Hubbard model at finite temperatures, aligning with previous zero-temperature findings.

Findings

The phase transition line agrees with earlier finite-temperature results.

The transition line approaches the zero-temperature transition point monotonically.

The method accurately captures the coexistence region of metallic and insulating phases.

Abstract

We consider a Mott transition of the Hubbard model in infinite dimensions. The dynamical mean- field theory is employed in combination with a continuous-time quantum Monte Carlo (CTQMC) method for an accurate description at low temperatures. From the double occupancy and the energy density, which are directly measured from the CTQMC method, we construct the phase diagram. We pay particular attention to the construction of the first-order phase transition line (PTL) in the co- existence region of metallic and insulating phases. The resulting PTL is found to exhibit reasonable agreement with earlier finite-temperature results. We also show by a systematic inclusion of low- temperature data that the PTL, which is achieved independently of the previous zero-temperature results, approaches monotonically the transition point from earlier zero-temperature studies.