We theoretically demonstrate that screw dislocation (SD), a 1D topological defect widely present in semiconductors, exhibits ubiquitously a new form of spin-orbit coupling (SOC) effect. Differing from the widely known conventional 2D Rashba-Dresselhaus (RD) SOC effect that typically exists at surfaces or interfaces, the deep-level nature of SD-SOC states in semiconductors readily makes it an ideal SOC. Remarkably, the spin texture of 1D SD-SOC, pertaining to the inherent symmetry of SD, exhibits a significantly higher degree of spin coherency than the 2D RD-SOC. Moreover, the 1D SD-SOC can be tuned by ionicity in compound semiconductors to ideally suppress spin relaxation, as demonstrated by comparative first-principles calculations of SDs in Si/Ge, GaAs, and SiC. Our findings therefore open a new door to manipulating spin transport in semiconductors by taking advantage of an otherwise detrimental topological defect.
Bibliographical noteFunding Information:
We thank S. B. Zhang, S.-H. Wei, and X. W. Zhang for helpful discussions. L. H. and B. H. acknowledge the support from the Science Challenge Project (No. TZ2016003), China Postdoctoral Science Foundation (No. 2017M610754), NSFC (Grants No. 11574024 and No. 11704021), and NSAF (No. U1530401). H. H., W. J., X. N., Y. Z., and F. L. acknowledge the support from U.S. DOE (Award No. DE-FG02-04ER46148). The work of V. Z. and M. G. L. was supported in part by NSF (Grants No. DMR-9632527 and No. DMR-9304912), DOE (Award No. DE-FG02-00ER45816), and the Alexander von Humboldt Foundation. Computations were performed at Tianhe2-JK at CSRC.
© 2018 American Physical Society.