Hole Spin Relaxation in an Ultrathin InAs Monolayer

We investigate the spin relaxation time of holes in an ultrathin neutral InAs monolayer (1.5 ML) and compare with that of electrons, using polarization-dependent time-resolved photoluminescence (TRPL) experiments. With excitation energies above the GaAs gap, we observe a rather slow relaxation of holes (tau(1h) = 196 +/- 17 ps) that is in the magnitude similar to electrons (tau(1e) = 354 +/- 32 ps) in this ultrathin sample. The results are in good agreement with earlier theoretical prediction, and the phonon scattering due to spin-orbit coupling is realized to play a dominant role in the carrier spin kinetics.

National Natural Science Foundation of China 10674131 60625405National Basic Research Program of China 2007CB924904 Knowledge Innovation Project of Chinese Academy of Sciences KJCX2.YW.W09 Hundred Talents Program of Chinese Academy of Sciences Supported by the National Natural Science Foundation of China under Grant Nos 10674131 and 60625405, the National Basic Research Program of China under Grant No 2007CB924904, the Knowledge Innovation Project of Chinese Academy of Sciences under Grant No KJCX2.YW.W09, and the Hundred Talents Program of Chinese Academy of Sciences.