Persistent Spin Textures in Nonpolar Chiral Systems

Abstract

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 $k.p$ 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.

References in corpus (9)

• An Exact SU(2) Symmetry and Persistent Spin Helix in a Spin-Orbit Coupled System
• Emergence of the persistent spin helix in semiconductor quantum wells
• Discovery of topological chiral crystals with helicoid arc states
• Weyl Node and Spin Texture in Trigonal Tellurium and Selenium
• Direct mapping of the formation of a persistent spin helix: Supplementary information
• Direct determination of spin orbit interaction coefficients and realization of the persistent spin helix symmetry
• Persistent spin helix on a wurtzite ZnO(10-10) surface: First-principles density-functional study
• Strain-induced large spin splitting and persistent spin helix at LaAlO${}_3$/SrTiO${}_3$ interface
• Reversible giant out-of-plane Rashba effect in two-dimensional Ga$XY$ ($X$= Se, Te; $Y$= Cl, Br, I) compounds for persistent spin helix