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. [ABSTRACT FROM AUTHOR]