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arXiv 2210.03059cond-mat.supr-concond-mat.str-el
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螺旋Rashba超导体中的磁激发

Magnetic excitations in the helical Rashba superconductor

Alireza Akbari, Peter Thalmeier

AI总结:

本文推导了具有强Rashba自旋轨道耦合的非中心对称超导体螺旋态的动力学自旋响应函数,揭示了配对与非配对区域激发、反常相干因子和螺旋自旋纹理导致的实空间与自旋空间各向异性,为通过非弹性中子散射识别螺旋超导态提供了特征指纹。

摘要:

我们研究了具有反演对称破缺和强Rashba自旋轨道耦合的非中心对称超导体螺旋态中的磁激发谱。为此,我们在导带强Rashba劈裂、超导能隙以及导致螺旋态中具有有限总动量的Cooper对稳定的外场存在下,推导了动力学自旋响应函数的一般表达式。该螺旋态的特征是动量空间中具有不同准粒子色散的配对态和非配对态区域。磁响应由以下因素决定:i) 配对区域和非配对区域内部及之间的激发;ii) 反常相干因子;iii) 由于能带螺旋Rashba自旋纹理而产生的额外自旋矩阵元。我们证明,其结果是动力学磁化率中出现典型的关联实空间和自旋空间各向异性,这将在非弹性中子散射研究中作为螺旋超导态的特征指纹被观测到。

英文摘要:

We investigate the magnetic excitation spectrum in the helical state of a noncentrosymmetric superconductor with inversion symmetry breaking and strong Rashba spin-orbit coupling. For this purpose, we derive the general expressions of the dynamical spin response functions under the presence of strong Rashba splitting of conduction bands, superconducting gap, and external field which lead to stabilization of Cooper pairs with finite overall momentum in a helical state. The latter is characterized by momentum space regions of paired and unpaired states with different quasiparticle dispersions. The magnetic response is determined by i) excitations within and between both paired and unpaired regions ii) anomalous coherence factors and iii) additional spin matrix elements due to helical Rashba spin texture of bands. We show that as a consequence typical correlated real space and spin space anisotropies appear in the dynamical susceptibility which would be observable as a characteristic fingerprint for a helical superconducting state in inelastic neutron scattering investigations.

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。

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