Mechanical Control of Spin Coherence in Semiconductors

The in-plane strain in thin GaAs epilayers is probed using time-resolved Kerr rotation (TRKR), photoluminescence, and optically-detected nuclear magnetic resonance (ODNMR) spectroscopies. Strain is introduced into n-type GaAs epilayers using a novel mechanical deformation technique that allows tunable control of the strain levels in the epilayer. Strain induced shifts in the electron g-factor and photoluminescence peaks are observed and characterized from T=5K to room temperature. The magnitude of the in-plane strain can be determined from a control sample set of non strain-relaxed epilayers with in-plane strain determined with x-ray diffraction. Our results show promise for mechanical control of electron and nuclear spin in semiconductor nanostructures.