Spin relaxation in GaAs(110) quantum wells

We investigated electron spin relaxation time ${\ensuremath{\tau}}_{s}$ in $\mathrm{GaAs}/\mathrm{AlGaAs}$ (110) quantum wells (QWs), in which a predominant spin scattering mechanism [D'yakonov-Perel' (DP) mechanism] for conventional (100) QWs is substantially suppressed; ${\ensuremath{\tau}}_{s}$ in (110) QWs was of nanosecond order at room temperature, more than an order of magnitude longer than that of the (100) counterpart. The mechanism responsible for the spin relaxation was examined by studying the quantized energy, electron mobility, and temperature dependences of ${\ensuremath{\tau}}_{s}$. The results suggest that in the absence of DP interaction, electron-hole exchange interaction limits ${\ensuremath{\tau}}_{\mathrm{s}}$ in a wide temperature range ( $\ensuremath{\sim}0--300\mathrm{K}$).