Cyclotron resonance of InAs/AlSb single quantum well in high magnetic fields and spin relaxation process

Abstract

Spin-split cyclotron resonance (CR) of InAs/AlSb single quantum well exhibits a new type hysteresis in strong magnetic fields at low temperature. Pulsed high magnetic fields up to 150T with a duration of 6μs were generated by the single turn coil technique. The hysteresis was observed in the up and down sweep process of the fields with Bmax≳ 60T. This suggests that a non-equilibrium spin-state in the lowest Landau level is induced due to a slow spin reversal rate 1/T1≈107s−1. Two mechanisms for the spin reversal process are proposed: (i) Direct LO–phonon process and (ii) Raman process associated with LO–phonon emission and acoustic phonon absorption. These processes can well explain the characteristic feature of the hysteresis.