Coexisting unconventional Rashba- and Zeeman-type spin splitting in Pb-adsorbed monolayer WSe2

Based on first-principles calculations, the unconventional Rashba- and Zeeman-type spin splitting can simultaneously coexist in the Pb-adsorbed monolayer WSe2 system. The first two adsorption configurations t (1) and t (2) show remarkable features under the spin-orbit coupling, in which two split energy branches show same spin states at the left or right side of Gamma, and the spin polarization is reversed for both Rashba band branches. For the second adsorption configuration, an energy gap was observed near the unconventional spin polarization caused by the repelled Rashba bands for avoid crossing, and this gap can produce non-dissipative spin current by applying the voltage. The results for t (2) configuration with spin reversal show that the repel band gap and Rashba parameter can be effectively regulated within the biaxial strain range of -8% to 6%. By changing the adsorption distance d between Pb and the neighboring Se atom layer, the reduced d caused the transfer from Rashba-type to Zeeman-type spin splitting. This predicted adsorption system would be promising for spintronic applications.

Automated summary

Based on first-principles calculations, the coexistence of unconventional Rashba- and Zeeman-type spin splitting is observed in the Pb-adsorbed monolayer WSe2 system. The spin splitting properties can be effectively regulated by adjusting the adsorption configuration and distance. This predicted adsorption system shows promise for spintronic applications.