Giant piezoresistance in AlAs 2D electron systems with antidot lattice

We report a novel giant piezoresistance effect in AlAs wide quantum well 2D electron system, patterned with an antidot lattice of about 1.0 $\mu $m period. At a low density of $\sim $ 3.5$\times $10$^{11}$/cm$^{2}$ and at T=0.3 K, the piezoresistance exhibits a strain gauge factor as large as 20,000, the largest value reported so far without magnetic field. Compared to the region without the antidot pattern, this antidot region represents $\sim $ 3.5$\times $ larger gauge factor and $\sim $ 5$\times $ wider dynamic range in piezoresistance. Such device may find important applications for super sensitive strain detection in mechanical microstructures.