Stripes, Antiferromagnetism, and the Pseudogap in the Doped Hubbard Model at Finite Temperature
Stripes, Antiferromagnetism, and the Pseudogap in the Doped Hubbard Model at Finite Temperature
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DOI：
10.1103/physrevx.11.031007
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发表时间：
2020-09
影响因子：
12.5
通讯作者：
A. Wietek;Yuan-Yao He;S. White;A. Georges;E. Stoudenmire
中科院分区：
文献类型：
--
作者：
A. Wietek;Yuan-Yao He;S. White;A. Georges;E. Stoudenmire
热涨落和量子涨落之间的相互作用控制着强关联电子系统中物质相之间的竞争。用最小纠缠典型热态(Metts)方法研究了宽度为4$的柱面上强耦合二维掺杂Hubbard模型的有限温度性质。我们发现了一个新的相，其特征是具有公度的短程反铁磁关联，并且在半填充条状相以上的温度下没有电荷有序，直到零温度。从反铁磁相到条状相的转变发生在温度T/t约0.05℃，并伴随着比热的阶梯状特征。我们发现在节点处的单粒子能隙最小，并且磁化率有一个极大值。这些特征与高温铜酸盐超导体的伪隙相有很大的相似之处。在零温、小格子尺寸和半填充三种极限情况下，使用各种不同的无偏数值方法对模拟结果进行了验证。
The interplay between thermal and quantum fluctuations controls the competition between phases of matter in strongly correlated electron systems. We study finite-temperature properties of the strongly coupled two-dimensional doped Hubbard model using the minimally-entangled typical thermal states (METTS) method on width $4$ cylinders. We discover that a novel phase characterized by commensurate short-range antiferromagnetic correlations and no charge ordering occurs at temperatures above the half-filled stripe phase extending to zero temperature. The transition from the antiferromagnetic phase to the stripe phase takes place at temperature $T/t \approx 0.05$ and is accompanied by a step-like feature of the specific heat. We find the single-particle gap to be smallest close to the nodal point at $\mathbf{k}=(\pi/2, \pi/2)$ and detect a maximum in the magnetic susceptibility. These features bear a strong resemblance to the pseudogap phase of high-temperature cuprate superconductors. The simulations are verified using a variety of different unbiased numerical methods in the three limiting cases of zero temperature, small lattice sizes, and half-filling.