Low temperature properties of the infinite-dimensional attractive Hubbard model

TL;DR

This paper studies the low-temperature behavior of the infinite-dimensional attractive Hubbard model using advanced computational methods, revealing superfluid stability and density of states characteristics in different regimes.

Contribution

It combines dynamical mean-field theory with quantum Monte Carlo to analyze superfluid properties and density of states in the attractive Hubbard model.

Findings

Superfluid state stability depends on density and interaction strength.

Heavy fermion behavior observed in dense systems above critical temperature.

Dip structures in density of states appear in dilute systems.

Abstract

We investigate the attractive Hubbard model in infinite spatial dimensions by combining dynamical mean-field theory with a strong-coupling continuous-time quantum Monte Carlo method. By calculating the superfluid order parameter and the density of states, we discuss the stability of the superfluid state. In the intermediate coupling region above the critical temperature, the density of states exhibits a heavy fermion behavior with a quasi-particle peak in the dense system, while a dip structure appears in the dilute system. The formation of the superfluid gap is also addressed.