Ubiquitous Ideal Spin-Orbit Coupling in a Screw Dislocation in\n Semiconductors

Abstract

We theoretically demonstrate that screw dislocation (SD), a 1D topological\ndefect widely present in semiconductors, exhibits ubiquitously a new form of\nspin-orbit coupling (SOC) effect. Differing from the widely known conventional\n2D Rashba-Dresselhaus (RD) SOC effect that typically exists at\nsurfaces/interfaces, the deep-level nature of SD-SOC states in semiconductors\nreadily makes it an ideal SOC. Remarkably, the spin texture of 1D SD-SOC,\npertaining to the inherent symmetry of SD, exhibits a significantly higher\ndegree of spin coherency than the 2D RD-SOC. Moreover, the 1D SD-SOC can be\ntuned by ionicity in compound semiconductors to ideally suppress spin\nrelaxation, as demonstrated by comparative first-principles calculations of SDs\nin Si/Ge, GaAs, and SiC. Our findings therefore open a new door to manipulating\nspin transport in semiconductors by taking advantage of an otherwise\ndetrimental topological defect.\n