Quantum Monte Carlo simulations of infinitely strongly correlated fermions

TL;DR

This paper uses quantum Monte Carlo simulations to study strongly correlated fermions in the 2D t-J model, revealing how hole number and J/t ratio influence magnetic states at very low temperatures.

Contribution

It introduces large-scale quantum Monte Carlo simulations of the 2D t-J model at very low temperatures, exploring magnetic properties with multiple holes.

Findings

No minus signs in one-hole J=0 case allow very low temperature simulations.

J/t  0.05 causes partial polarization, while higher J/t leads to minimal spin.

Two-hole systems show increased total spin at low temperatures.

Abstract

Numerical simulations of the two-dimensional t-J model in the limit $J/t \ll 1$ are performed for rather large systems (up to $N = 12 \times 12$) using a world-line loop-algorithm. It is shown that in the one-hole case with J=0, where no minus signs appear, very low temperatures ($\beta t \sim 3000$) are necessary in order to reach Nagaoka's state. $J/t \ltsim 0.05$ leads to the formation of partially polarized systems, whereas $J/t \gtsim 0.05 $ corresponds to minimal spin. The two-hole case shows enhanced total spin up to the lowest attainable temperatures ($\beta t = 150$).