We consider the feasibility offabricating planar superconductor-semiconductor-superconductor Josephson junctions in which the junction supercurrent is controlled by a gate electrode isolated from the junction by either a dielectric film (MOS-JOFET) or a Schottky barrier (MES-JOFET). We fin~ that device critical currents between ~ 1 and 100 f-lA and critical temperatures approxImately a few K appear possible. We discuss the circuit applications of such devices.

The authors have measured the magnetoresistance of one-dimensional GaAs heterojunction wires at temperatures down to 0.04 K and in magnetic fields of up to 1.2 T. At low magnetic fields they observe universal conductance fluctuations with a temperature dependence consistent with a temperature independent phase breaking length. This unexpected result is not predicted by theory and they speculate that it may be related to the breakdown of diffusive motion.

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An analysis of the Auger-parameter shifts between PbTe and the pure elements is shown to yield insight into mechanisms of core-hole screening and charge transfer in the ground state. A parametrized treatment of the Auger-parameter shifts in which the screening terms are treated in terms of a Jost-cavity model shows that the ground-state charge transfer in PbTe is less than 0.30e+0.06e. It is shown that core holes are screened more efficiently on Pb sites than on Te sites in PbTe, and that Te core holes are screened more efficiently in pure Te than in PbTe.