Superconducting thin film phase change material for latching microwave switches

We report the first superconducting thin film phase change material that has both a crystallization temperature above room temperature and makes a transition into a superconducting state within a temperature range measured here to be 0.5 ± 0.2 K. This opens the prospect for a latching microwave switch with an infinite cut-off frequency. The phase change material used is a mixture of SnTe and GeTe, which when a heat pulse is applied transforms between amorphous and crystalline states, latching into either the crystalline on-state or the amorphous off-state, depending upon the magnitude and duration of the pulse, and is reversible with the appropriate following pulse.