标题： 非极性手性系统中的持久自旋纹理 显示英文标题

标题： Persistent Spin Textures in Nonpolar Chiral Systems

摘要： 在本文中，我们提出了一种实现持久自旋纹理（PST）的新途径。 我们从对称性考虑表明，在非极性手性系统中，围绕具有$D_{2}$小群的高对称点的特定轨道特征的能带可能在低能$\bf{k.p}$模型哈密顿量中允许一个单独的自旋依赖项，这自然导致 PST。 考虑到布里渊区（BZ）中的$2D$平面，我们进一步认为，在这种手性系统中，由于 Dresselhaus 和 Weyl（径向）相互作用参数的强度相当，导致 PST 的出现，而这两个项的存在是由$D{_2}$对称性允许的。 最后，通过第一性原理密度泛函理论（DFT）计算，我们确定非极性手性化合物 Y$_3$TaO$_7$和 AsBr$_3$分别在导带和价带在$\Gamma$点附近表现出 PST，具有$D{_2}$小群，并且主要具有 Y$_3$TaO$_7$的 Ta-$d_{xz}$轨道特征和 AsBr$_3$的 Br-$p{_x}$轨道特征，证实了我们的总体策略。 我们对非极性手性系统中PST的实现结果，从而扩展了显示PST的材料种类，这些材料可用于自旋-轨道电子学的应用。 显示英文摘要

摘要： In this paper, we have proposed a novel route for the realisation of persistent spin texture (PST). We have shown from symmetry considerations that in non-polar chiral systems, bands with specific orbital characters around a high symmetry point with $D_{2}$ little group may admit a single spin dependent term in the low energy $\bf{k.p}$ model Hamiltonian that naturally leads to PST. Considering a $2D$ plane in the Brillouin zone (BZ), we have further argued that in such chiral systems the PST is transpired due to the comparable strengths of the Dresselhaus and Weyl (radial) interaction parameters where the presence of these two terms are allowed by the $D{_2}$ symmetry. Finally using first principles density functional theory (DFT) calculations we have identified that the non-polar chiral compounds Y$_3$TaO$_7$ and AsBr$_3$ displays PST for the conduction band and valence band respectively around the $\Gamma$ point having $D{_2}$ little group and predominantly Ta-$d_{xz}$ orbital character for Y$_3$TaO$_7$ and Br-$p{_x}$ orbital character for AsBr$_3$ corroborating our general strategy. Our results for the realisation of PST in non-polar chiral systems thereby broaden the class of materials displaying PST that can be employed for application in spin-orbitronics.