Characteristics of a free-standing superconducting nanobridge with an integrated heater fabricated using a self-aligned technique

We report on a novel method of controlling the supercurrent flow in a superconducting weaklink. We have fabricated a free-standing superconducting nanobridge with an integrated NiCr heater. This NiCr layer acts as a self-aligned mask for reactive ion etching and also as the normal metal heating element of the nanobridge. The heater is used to control the critical current of the superconducting weaklink part of the nanobridge; the free-standing nature of the nanobridge reduces the heater power required. We discuss the dependence of the current–voltage characteristics of the superconducting weaklink on heater current. This device has advantages over existing controllable weaklink devices.