Physica C: Superconductivity and its Applications ( IF 1.3 ) Pub Date : 2022-09-05 , DOI: 10.1016/j.physc.2022.1354141 Pavol Farkašovský
Projector quantum Monte Carlo calculations are used to examine superconducting correlations in the two-dimensional Hubbard model with exponentially decaying electron hopping amplitudes . It is shown that this type of hopping, which models more realistically (in comparison to the nearest-neighbor hopping) the situation in real transition-metal materials, stabilizes significantly the superconducting correlations in the -wave channel for electron concentrations above the quarter band filling, especially for . In this region the enhancement of the superconducting correlations at non-zero , against the classical Hubbard limit (), changes (depending on the electron concentration) from 2 in the worse case to 5 in the best case. Moreover, we have studied also the influence of the Coulomb interaction and a disorder on superconducting correlations. We have found that the Coulomb interaction enhances significantly superconducting correlations in the -wave channel, while a disorder suppresses them gradually, but they surprisingly persist up to the disorder strength comparable to the Coulomb interaction.
中文翻译:
具有远程电子跳跃的二维 Hubbard 模型中的超导相关性
投影量子蒙特卡罗计算用于检查二维哈伯德模型中的超导相关性,电子跳跃幅度呈指数衰减. 结果表明,这种类型的跳跃更真实地模拟了真实过渡金属材料中的情况(与最近邻跳跃相比),显着稳定了超导相关性电子浓度的波通道以上四分之一带填充,特别是对于. 在该区域中,非零超导相关性的增强, 反对经典的哈伯德极限 (),变化(取决于电子浓度)从最坏情况下的 2 到最好情况下的 5。此外,我们还研究了库仑相互作用的影响和超导相关性的紊乱。我们发现库仑相互作用显着增强了超导相关性波通道,虽然无序会逐渐抑制它们,但它们令人惊讶地持续到与库仑相互作用相当的无序强度。