Light-induced long-ranged disorder effect in ultradilute two-dimensional holes in GaAs heterojunction-insulated-gate field-effect-transistors
Comparing the results of transport measurements of strongly correlated two-dimensional holes in a GaAs heterojunction-insulated-gate field-effect-transistor obtained before and after a brief photoillumination, the light-induced disorder is found to cause qualitative changes suggesting altered carrier states. For charge concentrations ranging from 3×1010 down to 7×108 cm−2, the post-illumination hole mobility exhibits a severe suppression for charge densities below 2×1010 cm−2 while almost no change for densities above. The long-ranged nature of the disorder is identified. The temperature dependence of the conductivity is also drastically modified by the disorder reconfiguration from being nonactivated to activated.Comparing the results of transport measurements of strongly correlated two-dimensional holes in a GaAs heterojunction-insulated-gate field-effect-transistor obtained before and after a brief photoillumination, the light-induced disorder is found to cause qualitative changes suggesting altered carrier states. For charge concentrations ranging from 3×1010 down to 7×108 cm−2, the post-illumination hole mobility exhibits a severe suppression for charge densities below 2×1010 cm−2 while almost no change for densities above. The long-ranged nature of the disorder is identified. The temperature dependence of the conductivity is also drastically modified by the disorder reconfiguration from being nonactivated to activated.