Quantum Monte Carlo loop algorithm for the <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi><mo>−</mo><mi>J</mi></math></span> model

Beat Ammon; Hans Gerd Evertz; Naoki Kawashima; Matthias Troyer; Beat Frischmuth

doi:10.1103/PhysRevB.58.4304

Quantum Monte Carlo loop algorithm for the $t - J$ model

Beat Ammon, Hans Gerd Evertz, Naoki Kawashima, Matthias Troyer, and Beat Frischmuth

Phys. Rev. B 58, 4304 – Published 15 August 1998

Abstract

We propose a generalization of the quantum Monte Carlo loop algorithm to the $t - J$ model by a mapping to three coupled six-vertex models. The autocorrelation times are reduced by orders of magnitude compared to the conventional local algorithms. The method is completely ergodic and can be formulated directly in continuous time. We introduce improved estimators for simulations with a local sign problem. Some first results of finite-temperature simulations are presented for a $t - J$ chain, a frustrated Heisenberg chain, and $t - J$ ladder models.