论文标题
非常规手性效率半金属xy（x = co，rh; y = si，ge）中的螺旋脉冲旋转大厅和自旋旋转效果
Helicity-tunable spin Hall and spin Nernst effects in unconventional chiral fermion semimetals XY (X=Co, Rh; Y=Si, Ge)
论文作者
论文摘要
最近发现，在手性Cutic B20结构中的过渡金属单物质剂COSI，COGE，RHSI和RHGE在Spin-1/2 WFS以外具有非常规的手性手提丝，并且还表现出异国情调的物理现象，例如长期Fermi Arc表面状态，GME和量化的CPGE。因此，在这些非常规性手性效率半法中探索新型自旋相关的传输可能会为旋转型和旋转热量的新门打开新的门。在本文中，我们根据从头开始的相对论带结构计算研究了COSI家族中的固有的她和SNE。首先，我们发现与非手续立方金属不同，COSI家族有两个独立的非零SHC（SNC）张量元素，即$σ_{xy}^z $和$σ_{xz}^y $（$α__{$α__{xy}^z $ and $α__{xz} ement oons One One nement。此外，发现shc（$σ_{xy}^z $和$σ_{xz}^y $），并且发现手性结构的螺旋是相关的，从而使她能够检测结构的螺旋性以及手性费米恩的胆汁性。其次，她和Sne在某些Cosi家族中的内在含义很大。特别是，计算出的RHGE SHC高达-140（$ \ hbar $/e）（s/cm）。在室温下，计算出的Coge的SNC也很大，为-1.3（$ \ hbar $/e）（a/m k）。由于它们的半金属性质具有低电导率，因此这些拓扑半学可能具有较大的自旋大厅和旋转的Nernst角度，可与PT金属相媲美。这些化合物的SHC和SNC也可以通过通过化学掺杂或电控升起或降低拓扑节点来增加或降低$μ$。因此，我们的发现表明，COSI家族不仅会提供一个物质平台，以探索非常规性手性武器半学中新型的自旋传输和外来现象，而且还可以是开发更好的旋转和旋转热量的热量型热量器件的有希望的材料。
Transition metal monosilicides CoSi, CoGe, RhSi and RhGe in the chiral cubic B20 structure have recently been found to host unconventional chiral fermions beyond spin-1/2 WFs, and also exhibit exotic physical phenomena such as long Fermi arc surface states, GME and quantized CPGE. Thus, exploring novel spin-related transports in these unconventional chiral fermion semimetals may open a new door for spintronics and spin caloritronics. In this paper, we study the intrinsic SHE and SNE in the CoSi family based on ab initio relativistic band structure calculations. First, we find that unlike nonchiral cubic metals, the CoSi family have two independent nonzero SHC (SNC) tensor elements, namely, $σ_{xy}^z$ and $σ_{xz}^y$ ($α_{xy}^z$ and $α_{xz}^y$) instead of one element. Furthermore, the SHC ($σ_{xy}^z$ and $σ_{xz}^y$) and helicity of the chiral structure are found to be correlated, thus enabling SHE detection of structural helicity and also chiral fermion chirality. Second, the intrinsic SHE and SNE in some of the CoSi family are large. In particular, the calculated SHC of RhGe is as large as -140 ($\hbar$/e)(S/cm). The calculated SNC of CoGe is also large, being -1.3 ($\hbar$/e)(A/m K) at room temperature. Due to their semimetallic nature with low electrical conductivity, these topological semimetals may have large spin Hall and spin Nernst angles, being comparable to that of Pt metal. The SHC and SNC of these compounds can also be increased by raising or lowering $μ$ to, e.g., the topological nodes, via either chemical doping or electrical gating. Our findings thus indicate that the CoSi family not only would provide a material platform for exploring novel spin-transports and exotic phenomena in unconventional chiral fermion semimetals but also could be promising materials for developing better spintronic and spin caloritronic devices.
