The pairing symmetries in the two-dimensional Hubbard model

Using finite-temperature determinant quantum Monte Carlo algorithm, we study the effective pairing susceptibility of different pairing channels in the two-dimensional Hubbard model, to determine the dominant pairing channels in different parameter regimes. At half-filling, we can access low enough temperatures and find the dominant pairing is the d(x2-y2)-wave. While in the doping case, we are limited to some finite temperatures due to the sign problem of the determinant quantum Monte Carlo algorithm. When the doping is not very heavy, the dominant pairing channel keeps to be the d(x2-y2)-wave. While at low electron densities, the dominant pairing channel switches to the d(xy)-wave. In additional, there's a small region of the s*-wave pairing at weak interaction strength and close to half-filling. Except for the s*-wave regime, the interaction strength and the temperature seem to only have slight effect on the dominant pairing channels. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Using finite-temperature determinant quantum Monte Carlo algorithm, the study investigates the effective pairing susceptibility in the two-dimensional Hubbard model, identifying the dominant pairing channels in different parameter regimes. The dominant pairing is found to be d(x2-y2)-wave at half-filling, while in doping cases, the dominant channel may switch between d(x2-y2)-wave and d(xy)-wave.