Modified Monte Carlo method with the heat bath algorithm for a model cuprate

Abstract

The results of numerical simulation using a modified Monte Carlo method with a heat bath algorithm for the pseudospin model of cuprates are presented. The temperature phase diagrams are constructed for various degrees of doping and for various parameters of the model, and the effect of local correlations on the critical temperatures of the model cuprate is investigated. It is shown that, in qualitative agreement with the results of the mean field, the heat bath algorithm leads to a significant decrease in the estimate of critical temperatures due to more complete accounting of fluctuations, and also makes it possible to detect phase inhomogeneous states. The possibility of using machine learning to accelerate the heat bath algorithm is discussed.

Figures (5)

• Figure 1: The concentration dependences of critical temperatures for different values of the parameter of local charge-charge correlations.
• Figure 2: Values of the critical temperature $T_{CO}$ obtained in the mean-field approximation (dotted line) and in the MC method (solid line). The values of the charge order parameter are shown on the right panel. The nonzero model parameters are $\Delta=0.1$, $V=0.25$.
• Figure 3: Values of the critical temperature $T_{AFM}$ obtained in the mean-field approximation (dotted line) and in the MC method (solid line). The dashed line shows the boundary of the phase separation region. The values of the antiferromagnetic order parameter are shown on the right panel. The nonzero model parameters are $\Delta=0.1$, $J=1$.
• Figure 4: Values of the critical temperature $T_{BS}$ obtained in the mean-field approximation (dotted line) and in the MC method (solid line). The values of the order parameter of the superfluid phase are shown on the right panel. The nonzero model parameters are $\Delta=0.1$, $t_b=1$.
• Figure 5: Values of the critical temperature $T_p$ obtained in the mean-field approximation (dotted line) and in the MC method (solid line). The dashed line shows the boundary of the phase separation region. The values of the order parameter for the P phase are shown on the right panel. The nonzero model parameters are $\Delta=0.1$, $t_p=1$.