Rashba and Dresselhaus Spin-Splittings in Semiconductor Quantum Wells   Measured by Spin Photocurrents
  The spin-galvanic effect and the circular photogalvanic effect induced by terahertz radiation are applied to determine the relative strengths of Rashba and Dresselhaus band spin-splitting in (001)-grown GaAs and InAs based two dimensional electron systems. We observed that shifting the $\delta$-doping plane from one side of the quantum well to the other results in a change of sign of the photocurrent caused by Rashba spin-splitting while the sign of the Dresselhaus term induced photocurrent remains. The measurements give the necessary feedback for technologists looking for structures with equal Rashba and Dresselhaus spin-splittings or perfectly symmetric structures with zero Rashba constant. 
S. Giglberger, L.E. Golub, V.V. Bel'kov, S.N. Danilov, D. Schuh, Ch.   Gerl, F. Rohlfing, J. Stahl, W. Wegscheider, D. Weiss...