Controlling the persistent spin helix with strain induced spin-orbit coupling

We use transient spin grating spectroscopy to study the persistent spin helix (PSH) state of the 2D electron gas. The PSH is a meta-stable helical spin density wave that emerges as a result of increased symmetry when the Rashba and Dresselhaus spin-orbit coupling terms are balanced, and which offers great promise as a means of controlling large ensembles of spins. We demonstrate that the spin-orbit symmetry, and the PSH dynamics, can be manipulated \textit{in-situ} by the application of uniaxial strain. This strain induces spin-orbit coupling with precisely the same symmetry as the Rashba term, allowing us to effectively tune the Rashba/Dresselhaus ratio in a single sample. This work is supported by DMSE office of BES-DOE, NSF, MARCO, ASEE and CNID.