The Absence Of The Rashba Spin-Splitting In Undoped Asymmetric Quantum Wells

It is widely accepted that quantum wells with potential profiles lacking inversion symmetry will exhibit spin‐split conduction band states due to the Rashba spin‐orbit interaction. Here we measure conduction band splitting for undoped asymmetric and symmetric GaAs/AlGaAs quantum wells in the absence of electric fields. Surprisingly the conduction band spin‐splitting measured in asymmetric quantum wells is no greater than that measured in symmetric quantum wells. This is a consequence of Ehrenfests theorem and the fact that the conduction and valence band edge profiles are related by a constant factor.