A non-adiabatically driven electron in a quantum wire with spin–orbit interaction

An exact solution is derived for the wavefunction of an electron in a semiconductor quantum wire with spin–orbit interaction and driven by external time-dependent harmonic confining potential. The formalism allows analytical expressions for various quantities to be derived, for example spin and pseudo-spin rotations, energy and occupation probabilities for excited states. It is demonstrated how perfect spin and pseudo-spin flips can be achieved at high frequencies of the order of ω, the confining potential level spacing. By an appropriately chosen driving term, spin manipulation can be exactly performed far into the non-adiabatic regime. The implications for spin-polarized emission and spin-dependent transport are also discussed. (paper)