Theory of a pair density wave on a quasi-one-dimensional lattice in the Hubbard model
Theory of a pair density wave on a quasi-one-dimensional lattice in the Hubbard model
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哈伯德模型中准一维晶格上的偶密度波理论
DOI：
10.1103/physrevb.104.094506
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发表时间：
2021
影响因子：
3.7
通讯作者：
Tanaka Yukio
中科院分区：
文献类型：
--
作者：
Yoshida Soma;Yada Keiji;Tanaka Yukio
本文研究了基于随机相位近似（RPA）和涨落交换近似（FLEX）的Hubbard模型中准一维晶格的超导不稳定性。我们发现，自旋单重态对密度波（PDW单重态）的质心动量为可以稳定时，一维变得突出的完美嵌套的费米面。所得到的对是偶频和奇频单重态的混合物。占主导地位的偶频分量在费米面上没有节线。当在FLEX近似中引入自能修正时，这种PDW单重态比RPA更有利。
In this study we examine the superconducting instability of a quasi-one-dimensional lattice in the Hubbard model based on the random-phase approximation (RPA) and the fluctuation exchange (FLEX) approximation. We find that a spin-singlet pair density wave (PDW singlet) with a center-of-mass momentum ofcan be stabilized when the one dimensionality becomes prominent toward the perfect nesting of the Fermi surface. The obtained pair is a mixture of even-frequency and odd-frequency singlet ones. The dominant even-frequency component does not have nodal lines on the Fermi surface. This PDW-singlet state is more favorable as compared to RPA when self-energy correction is introduced in the FLEX approximation.