Noncentrosymmetric metals such as Li$_2$(Pd$_{1-x}$Pt$_x$)$_3$B have different Fermi surface topology below and above the band touching point where spin-degeneracy is not lifted by the spin-orbit coupling. We investigate thermoelectric and optical response as probes for this Fermi surface topology change. We show that the chemical potential displays a dimensional crossover from a three-dimensional to one-dimensional characteristics as the descending Fermi energy crosses the band touching point. This dimensional crossover is due to the existence of different Fermi surface topology above and below the band touching point. We obtain an exact expression of relaxation time due to short-range scatterer by solving Boltzmann transport equations self-consistently. The thermoelctric power and figure of merit are significantly enhanced as the Fermi energy goes below the band touching point owing to the underlying one-dimensional-like nature of noncentrosymmteric bulk metals. The value of thermoelectric figure of merit goes beyond two as the Fermi energy approaches to the van Hove singularity for lower spin-orbit coupling. Similarly, the studies of the zero-frequency and finite-frequency optical conductivities in the zero-momentum limit reflect the nature of topological change of the Fermi surface. The Hall coefficient and optical absorption width exhibit distinct signatures in response to the changes in Fermi surface topology.
Nonreciprocal thermal and thermoelectric transport of electrons in noncentrosymmetric crystals
非互易输运现象表明，前向流和反向流不同，并归因于破缺反转对称。在本文中，我们研究了由反转对称性破缺晶体结构引起的电子系统的热输运和热电输运的非互易性。在电场和温度梯度下，利用弛豫时间近似的Boltzmann方程，导出了二阶非线性电、热、热传导系数。本文中出现的所有二阶电导率都是由两个函数及其导数描述的，并且它们以与线性电导率相同的方式相互关联，例如通过Wiedemann-Franz定律。我们发现，非零温度极限下的热输运系数出现在非线性电导率，这在足够低的温度下主导热输运。在$1H$单层的过渡金属dichalcogenides MoS $_2$和极性半导体BiTeX（X=I，Br）的非线性电导率和可能的可观察到的量估计。
Switching magnetic texture via in-plane magnetic field in noncentrosymmetric dipolar magnets: From skyrmions to antiskyrmions and nontopological magnetic bubbles
Electric, thermal, and thermoelectric magnetoconductivity for Weyl/multi-Weyl semimetals in planar Hall set-ups induced by the combined effects of topology and strain
Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所，北京凝聚态物理国家实验室）；University of Chinese Academy of Sciences（中国科学院大学）；Condensed Matter Physics Data Center, Chinese Academy of Sciences（中国科学院凝聚态物理数据中心）
