Microwave Power Dependence of Electric Dipole Spin Resonance

The electric dipole spin resonance (EDSR) mediated by spin–orbit interaction (SOI) in GaAs‐ and hole‐based quantum dots formed within a quantum well is analyzed. Using the Schrieffer–Wolff transformation to the lowest order in SOI strength and a rotating frame, the effective Hamiltonian for EDSR is derived. When the SOI Hamiltonian is proportional to the cube of the momentum operator, the effective Hamiltonian includes a residual spin‐momentum coupling term, which becomes more pronounced for higher orbital excitations induced by the microwave field. To account for the coupling between orbital motion and the environment, the Gorini–Kossakowski–Sudarshan–Lindblad master equation is employed and two limiting cases: slow and fast orbital relaxation are analyzed. The results reveal that cubic SOI leads to a nonlinear dependence of the Rabi frequency on the applied microwave amplitude. Moreover, the fidelity of spin manipulations deteriorates due to residual spin–orbit couplings that induce spin relaxation.