Systematic gate-controlled reentrant conductance of a superconductor-semiconductor two-dimensional electron gas junction

We have investigated the temperature and voltage dependencies of the conduc tance in a superconductor-semiconductor two-dimensional electron gas (2DEG) junction with a gate. We observed the systematically controlled reentrant behavior of the conductance by using the gate to change diffusion constant of the 2DEG. We confirmed that the correlation energy of the proximity corr ection to the conductance is proportional to the diffusion constant of the normal part. We also examined the effect of the magnetic field on the reent rance and found that even a small magnetic field changed it drastically. [S 0163-1829(99)50918-1].