Infrared absorption in a quantum wire in the presence of spin-orbit coupling: a technique to measure different types of spin-orbit interaction strengths

摘要

We show that the dominant absorption peak due to inter-subband transition ina gated quantum wire, with two occupied subbands, will split into a main peakand two satellite peaks if both Rashba and Dresselhaus spin-orbit interactionsare present. One satellite peak will be red-shifted, and the otherblue-shifted. From the relative intensity of either satellite peak, and themagnitude of the red- or blue-shift, we can determine both Rashba andDresselhaus interaction strengths separately, if we also carry out a Hallmeasurement to determine the carrier concentration and a quantized conductancestep measurement to determine the energy separation between subbands. Thismethod may be a convenient alternative to usual magneto-transport measurementsused to measure spin orbit interaction strengths. It is also more powerfulbecause it allows us to measure the strengths of the two types of interactionsseparately.