Tunable Giant Rashba-type Spin Splitting in PtSe2/MoSe2 Heterostructure
Abstract
We report a giant Rashba-type spin splitting in two-dimensional heterostructure PtSe2/MoSe2 with first-principles calculations. We obtain a large value of spin splitting energy 110 meV at the momentum offset k0=0.23 -1 around point, arising from the emerging strong interfacial spin-orbital coupling induced by the hybridization between PtSe2 and MoSe2. Moreover, we find that the band dispersion close to valence band maximum around point can be well approximated by the generalized Rashba Hamiltonian H(k||)=-2 k||22m+c k||+αR σ·(k|| × z). It is found that the generalized Rashba constant ηR=c+αR in PtSe2/MoSe2 is as large as 1.3 eV·, and importantly ηR can be effectively tuned by biaxial strain and external out-of-plane electrical field, presenting a potential application for the spin field-effect transistor. In addition, with the spin-valley physics at K/K' points in monolayer MoSe2, we propose a promising model for spin field-effect transistor with opto-valleytronic spin injection based on PtSe2/MoSe2 heterostructure.