Sadeghi Elham, Rezania Hamed
Physics Department, Razi Univerity, Kermanshah, Iran.
Sci Rep. 2022 May 20;12(1):8523. doi: 10.1038/s41598-022-12588-5.
In this paper, the transport properties of a two-dimensional Lieb lattice that is a line-centered square lattice are investigated in the presence of magnetic field and spin-orbit coupling. Specially, we address the temperature dependence of electrical and thermal conductivities as well as Seebeck coefficient due to spin-orbit interaction. We have exploited Green's function approach in order to study thermoelectric and transport properties of Lieb lattice in the context of Kane-Mele model Hamiltonian. The results for Seebeck coefficient show the sign of thermopower is positive in the presence of spin-orbit coupling. Also the temperature dependence of transport properties indicates that the increase of spin-orbit coupling leads to decrease thermal conductivity however the decrease of gap parameter causes the reduction of thermal conductivity. There is a peak in temperature dependence of thermal conductivity for all values of magnetic fields and spin-orbit coupling strengths. Both electrical and thermal conductivities increase with increasing the temperature at low amounts of temperature due to the increasing of transition rate of charge carriers and excitation of them to the conduction bands. Also we have studied the temperature dependence of Seebeck coefficient of Lieb monolayer due to both spin orbit coupling and magnetic field factors in details.
在本文中，研究了作为线心方格晶格的二维Lieb晶格在存在磁场和自旋轨道耦合时的输运性质。特别地，我们探讨了由于自旋轨道相互作用导致的电导率、热导率以及塞贝克系数的温度依赖性。我们采用格林函数方法，以便在凯恩 - 梅勒模型哈密顿量的背景下研究Lieb晶格的热电和输运性质。塞贝克系数的结果表明，在存在自旋轨道耦合时，热电动势的符号为正。此外，输运性质的温度依赖性表明，自旋轨道耦合的增加会导致热导率降低，然而能隙参数的减小也会使热导率降低。对于所有磁场值和自旋轨道耦合强度，热导率的温度依赖性都存在一个峰值。在低温下，由于载流子跃迁速率的增加以及它们被激发到导带，电导率和热导率都随温度升高而增加。此外，我们还详细研究了由于自旋轨道耦合和磁场因素导致的Lieb单层塞贝克系数的温度依赖性。
