Switchable S = 1/2 and J = 1/2 Rashba bands in ferroelectric halide perovskites.
The Rashba effect is spin degeneracy lift originated from spin-orbit coupling under inversion symmetry breaking and has been intensively studied for spintronics applications. However, easily implementable methods and corresponding materials for directional controls of Rashba splitting are still lacking. Here, we propose organic-inorganic hybrid metal halide perovskites as 3D Rashba systems driven by bulk ferroelectricity. In these materials, it is shown that the helical direction of the angular momentum texture in the Rashba band can be controlled by external electric fields via ferroelectric switching. Our tight-binding analysis and first-principles calculations indicate that S = 1/2 and J = 1/2 Rashba bands directly coupled to ferroelectric polarization emerge at the valence and conduction band edges, respectively. The coexistence of two contrasting Rashba bands having different compositions of the spin and orbital angular momentum is a distinctive feature of these materials. With recent experimental evidence for the ferroelectric response, the halide perovskites will be, to our knowledge, the first practical realization of the ferroelectric-coupled Rashba effect, suggesting novel applications to spintronic devices.
Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea;
Minsung
M
Kim
Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208; and.
Jino
J
Im
Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208; and.
Arthur J
AJ
Freeman
Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea; jihm@snu.ac.kr jinhs76@snu.ac.kr.
Jisoon
J
Ihm
Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea;Center for Correlated Electron Systems, Institute for Basic Science, Seoul 151-747, Korea jihm@snu.ac.kr jinhs76@snu.ac.kr.
Hosub
H
Jin
D017610:Calcium Compounds / Q000737:chemistry*; D003198:Computer Simulation; D003460:Crystallization / Q000379:methods; D004581:Electronics / Q000379:methods*; D007501:Iron / Q000737:chemistry; D008744:Methylamines / Q000737:chemistry; D008956:Models, Chemical; D049329:Nanostructures / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry; D010087:Oxides / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
D017610:Calcium Compounds; D008744:Methylamines; D009930:Organic Chemicals; D010087:Oxides; C059910:perovskite; C027451:methylamine; D014025:Titanium; D007501:Iron
density functional theory; effective Hamiltonian; electronic structure