Valley spin-acoustic resonance in monolayer MoS₂

Monolayer molybdenum disulphide (MoS_2) is a strong candidate material to study spin-valley coupled physics in 2D materials. Its unique band structure consists of spin-split subbands crossing each other at finite momenta with opposite spin orientation in both the valleys. When exposed to Rayleigh surface acoustic waves, strain-induced pseudomagnetic fields couple with spin resulting in spin-phonon interaction. We theoretically predict the occurrence of spin acoustic resonance accompanied by an acoustoelectric current due to spin-flip transitions between the spin-split subbands. We calculate the transition probabilities, obtain the conditions for observing spin acoustic resonance and calculate and study the behaviour of the acoustoelectric current. On breaking time reversal symmetry, both the spin acoustic resonance and acoustoelectric current become valley sensitive paving the way for acousto-electric spectroscopy of valley selective phenomena.