Supercurrents in two-dimensional electron systems

In this contribution we present studies on the control of supercurrents in semiconductor/superconductor hybrid devices. We demonstrate how the field-effect and the injection of hot electrons can be utilized to influence the magnitude of supercurrents that are induced in the two-dimensional electron system of an InAs heterostructure sandwiched between superconducting Nb electrodes. No amplification is obtained in the field-effect device, however the current gain in the device controlled by hot electron injection exceeds unity.