Anisotropic low-temperature piezoresistance in (311)A GaAs two-dimensional holes

Abstract

We report low-temperature resistance measurements in a modulation-doped, (311)A GaAs two-dimensional hole system as a function of applied in-plane strain. The data reveal a strong but anisotropic piezoresistance whose magnitude depends on the density as well as the direction along which the resistance is measured. At a density of $1.6\times 10^{11}$ cm${}^{-2}$ and for a strain of about $2\times 10^{-4}$ applied along [01$\bar{1}$], e.g., the resistance measured along this direction changes by nearly a factor of two while the resistance change in the [$\bar{2}$33] direction is less than 10% and has the opposite sign. Our accurate energy band calculations indicate a pronounced and anisotropic deformation of the heavy-hole dispersion with strain, qualitatively consistent with the experimental data. The extremely anisotropic magnitude of the piezoresistance, however, lacks a quantitative explanation.

4 pages. Submitted to Applied Physics Letters

References in corpus (3)

• Valley susceptibility of an interacting two-dimensional electron system
• Low-temperature, in situ tunable, uniaxial stress measurements in semiconductors using a piezoelectric actuator
• Giant low-temperature piezoresistance effect in AlAs two-dimensional electrons

Cited by in corpus (3)

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• Strain-induced Fermi contour anisotropy of GaAs 2D holes