PRESSURE-INDUCED TRANSITION OF 2DEG IN δ-DOPED GaAs TO INSULATING STATE

Abstract

The tunneling and the lateral conductance of 2DEG formed in the GaAs with the δ-doped layer were measured simultaneously at hydrostatic pressures at helium temperatures. The resistivity of the δ-doped layer sharply increases by > 3 orders of magnitude at about 2 GPa, and its temperature coefficient changes from ~ - 0.04 to ~ - 4 K -1. The tunneling resistance shows only slight change of exponential behavior at about 1.5 GPa, while a drastic change of the Zero Bias Anomaly (ZBA) takes place just at the metal–insulator transition. Such a behavior is interpreted in terms of pressure dependence of the GaAs band structure and the DX-level position.