arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 2101.08285cond-mat.str-el
收藏

非谐Holstein模型的量子Monte Carlo研究

Quantum Monte Carlo study of an anharmonic Holstein model

G. Paleari, F. Hébert, B. Cohen-Stead, K. Barros, R. T. Scalettar, G. G. Batrouni

摘要:

通过在声子势能中引入一个四次项,研究了非谐性对描述巡游费米子和局域量子声子耦合的Holstein模型物理性质的影响.我们发现,这个非谐项的存在下,减少了在半填充的电荷密度波相位(CDW)的程度,以及过渡温度到这个阶段。掺杂远离半填充,我们观察到的CDW和一个均匀的相位,这也是目前在谐波模型之间的一阶相变。此外,我们还研究了掺杂区超导极化率的演化,发现非谐性可以增强超导响应。

英文摘要:

We study the effects of anharmonicity on the physics of the Holstein model, which describes the coupling of itinerant fermions and localized quantum phonons, by introducing a quartic term in the phonon potential energy. We find that the presence of this anharmonic term reduces the extent of the charge density wave phase (CDW) at half-filling as well as the transition temperature to this phase. Doping away from half-filling, we observe a first order phase transition between the CDW and a homogeneous phase which is also present in the harmonic model. In addition, we study the evolution of the superconducting susceptibility in the doped region and show that anharmonicity can enhance the superconducting response.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑