Absence of hysteresis at the mott-hubbard metal-insulator transition in infinite dimensions

Abstract

The nature of the Mott-Hubbard metal-insulator transition in the infinite-dimensional Hubbard model is investigated by Quantum Monte Carlo simulations down to temperature T=W/140 (W=bandwidth). Calculating with significantly higher precision than in previous work, we show that the hysteresis below T_(IPT)\simeq 0.022W, reported in earlier studies, disappears. Hence the transition is found to be continuous rather than discontinuous down to at least T=0.325T_(IPT). We also study the changes in the density of states across the transition, which illustrate that the Fermi liquid breaks down before the gap opens. © 1999 The American Physical Society.