Strain-induced resistance anisotropy near the FQHE v=5/2 in two-dimensional GaAs single quantum wells*

We report strain-dependent low temperature magnetotransport measurements of a two-dimensional electrons gas confined in GaAs single quantum wells. The samples are mounted to a piezoelectric-based strain device with which we can apply, and vary, tensile strain in the quantum well in situ. With this apparatus we have achieved strain as large as ~0.5% in GaAs quantum wells at cryogenic temperatures. We find that with increasing strain with a high magnetic field applied causes the magnetoresistance of the two-dimensional electron system confined in the quantum well to develop anisotropic resistance near the FQHE v = 5/2. Additionally, we find that this strain and field induced resistance anisotropy is caused by a meta-stable phase that has a temperature dependent decay back to its isotropic state.