The theory of transport in helical spin-structure crystals
The theory of transport in helical spin-structure crystals
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螺旋自旋结构晶体中的输运理论
DOI：
10.1088/1361-648x/ac9d7c
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Dahnovsky, Yuri
中科院分区：
文献类型：
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作者：
Zadorozhnyi, Andrei;Dahnovsky, Yuri
我们研究了自旋螺旋单晶中的螺旋结构。在螺旋性势能的连续近似中，简单电子带分裂成两个非抛物线带。对于低交换积分，较低的带被描述为在螺旋度轴的方向上具有鞍形的表面。利用Boltzmann方程和声子弛豫，我们发现了电流与电场和螺旋度轴之间的夹角的依赖关系，从而导致电导率中平行和垂直于电场的分量。后者可以解释为平面霍尔效应。此外，我们发现跃迁速率依赖于允许带间跃迁的电子自旋。电导率与化学势μ呈非线性关系。我们解释这种效果的干涉带各向异性，自旋守恒，带间跃迁。所提出的理论与球模型的有效质量近似的传导电子可以阐明非线性的依赖关系，可以在实验中确定。我们发现，在从螺旋到铁磁状态的相变中，平行电阻率随温度的变化的理论和实验数据之间有很好的一致性。
We study helical structures in spin-spiral single crystals. In the continuum approach for the helicity potential energy the simple electronic band splits into two non-parabolic bands. For low exchange integrals, the lower band is described by a surface with a saddle shape in the direction of the helicity axis. Using the Boltzmann equation with the relaxation due to acoustic phonons, we discover the dependence of the current on the angle between the electric field and helicity axis leading to the both parallel and perpendicular to the electric field components in the electroconductivity. The latter can be interpreted as a planar Hall effect. In addition, we find that the transition rates depend on an electron spin allowing the transition between the bands. The electric conductivities exhibit nonlinear behaviors with respect to chemical potential µ. We explain this effect as the interference of the band anisotropy, spin conservation, and interband transitions. The proposed theory with the spherical model in the effective mass approximation for conduction electrons can elucidate nonlinear dependencies that can be identified in experiments. We find the excellent agreement between the theoretical and experimental data for parallel resistivity depending on temperature at the phase transition from helical to ferromagnetic state in a