TY - JOUR
T1 - Ferri-chiral compounds with potentially switchable Dresselhaus spin splitting
AU - Huang, Pu
AU - Xia, Zhiguo
AU - Gao, Xiaoqing
AU - Rondinelli, James M.
AU - Zhang, Xiuwen
AU - Zhang, Han
AU - Poeppelmeier, Kenneth R.
AU - Zunger, Alex
N1 - Funding Information:
We thank Xinbo Chen for helpful discussion and preparation of the figures on spin textures. C.U. and N.U. were supported by the NSF-DMR EPM program under Grants No. DMR-1806939 and No. DMR-1806912, respectively. J.M.R. acknowledges funding from the Army Research Office (W911NF-15-1-0017). The work in China was supported by National Natural Science Foundation of China (Grants No. 11774239, No. 11804230, No. 51722202, and No. 61827815), the National Key R&D Program of China (Grant No. 2016YFB0700700), and the Shenzhen Science and Technology Innovation Commission (Grants No. JCYJ20170818093035338, No. KQTD20170810105439418, No. KQTD20180412181422399, and No. ZDSYS201707271554071).
PY - 2020/12/14
Y1 - 2020/12/14
N2 - Spin splitting of energy bands can be induced by relativistic spin-orbit interactions in materials without inversion symmetry. Whereas polar space-group symmetries permit Rashba (R-1) spin splitting with helical spin textures in momentum space, which could be reversed upon switching a ferroelectric polarization via applied electric fields, the ordinary Dresselhaus effect (D-1A) is active in materials exhibiting nonpolar noncentrosymmetric crystal classes with atoms occupying exclusively nonpolar lattice sites. Consequently, the spin-momentum locking induced by D-1A is not electric field switchable. Here we find a type of ferri-chiral materials with an alternative type of Dresselhaus symmetry, referred to as D-1B, exhibiting crystal class constraints similar to D-1A (all dipoles add up to zero), but unlike D-1A, at least one polar site is occupied. The spin splitting is associated with the crystalline chirality, which in principle could be reversed upon a change in chirality. Focusing on alkali metal chalcogenides, we identify NaCu5S3 in the nonenantiomorphic ferri-chiral structure, which exhibits CuS3 chiral units differing in the magnitude of their Cu displacements. We then synthesize NaCu5S3 (space group P6322) and confirm its ferri-chiral structure with powder x-ray diffraction. Our electronic structure calculations demonstrate it exhibits D-1B spin splitting as well as a ferri-chiral phase transition, revealing spin splitting interdependent on chirality. Our electronic structure calculations show that a few percent biaxial tensile strain can reduce (or nearly quench) the switching barrier separating the monodomain ferri-chiral P6322 states. We compute the circular dichroism absorption spectrum of the two ferri-chiral orientations and discuss what type of external stimuli might switch the chirality so as to reverse the (nonhelical) Dresselhaus D-1B spin texture. Our study suggests the design of ferri-chiral crystals as potential spintronic and optoelectronic materials.
AB - Spin splitting of energy bands can be induced by relativistic spin-orbit interactions in materials without inversion symmetry. Whereas polar space-group symmetries permit Rashba (R-1) spin splitting with helical spin textures in momentum space, which could be reversed upon switching a ferroelectric polarization via applied electric fields, the ordinary Dresselhaus effect (D-1A) is active in materials exhibiting nonpolar noncentrosymmetric crystal classes with atoms occupying exclusively nonpolar lattice sites. Consequently, the spin-momentum locking induced by D-1A is not electric field switchable. Here we find a type of ferri-chiral materials with an alternative type of Dresselhaus symmetry, referred to as D-1B, exhibiting crystal class constraints similar to D-1A (all dipoles add up to zero), but unlike D-1A, at least one polar site is occupied. The spin splitting is associated with the crystalline chirality, which in principle could be reversed upon a change in chirality. Focusing on alkali metal chalcogenides, we identify NaCu5S3 in the nonenantiomorphic ferri-chiral structure, which exhibits CuS3 chiral units differing in the magnitude of their Cu displacements. We then synthesize NaCu5S3 (space group P6322) and confirm its ferri-chiral structure with powder x-ray diffraction. Our electronic structure calculations demonstrate it exhibits D-1B spin splitting as well as a ferri-chiral phase transition, revealing spin splitting interdependent on chirality. Our electronic structure calculations show that a few percent biaxial tensile strain can reduce (or nearly quench) the switching barrier separating the monodomain ferri-chiral P6322 states. We compute the circular dichroism absorption spectrum of the two ferri-chiral orientations and discuss what type of external stimuli might switch the chirality so as to reverse the (nonhelical) Dresselhaus D-1B spin texture. Our study suggests the design of ferri-chiral crystals as potential spintronic and optoelectronic materials.
UR - http://www.scopus.com/inward/record.url?scp=85098230106&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85098230106&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.102.235127
DO - 10.1103/PhysRevB.102.235127
M3 - Article
AN - SCOPUS:85098230106
VL - 102
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 23
M1 - 235127
ER -