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 electron gas (2DEG) confined in GaAs single quantum wells. The samples are mounted to a piezoelectric-based strain device with which we can, in situ, apply and vary tensile strain. With this apparatus, we have achieved strain as large as ~0.5% in GaAs quantum wells at cryogenic temperatures. We find that increasing strain causes the magnetoresistance of the 2DEG confined in the quantum well to become anisotropic near the filling factor v = 5/2. Additionally, we find that the effects of strain are highly dependent on the magnitude of the magnetic field applied. These anisotropic states are metastable and resume an isotopic state after a temperature dependent decay.