Description:

In multi-terminal Josephson junctions (MTJJ), several superconducting contacts are made to a common non-superconducting region. As a result, the state of a MTJJ is dependent of superconducting phase differences between several pairs of contacts. This 2\pi periodic dependence on several variables is reminiscent of the Bloch bands in a crystal, making the MTJJ an interesting medium for engineering various toy models. I present our recent experimental results on MTJJ made of graphene, focusing on the effects of classical dynamics. Our main focus is the “multiplet” resonances observed at commensurate voltages across the junctions n V_1 = m V_2 with integer n and m. We show that these resonances can be established via synchronization of the junction dynamics due to a mechanism  analogous to the Kapitza pendulum. In a very recent development, a MTJJ allows us to make a superconducting diode with an efficiency approaching 100%.

Speaker: Gleb Finkelstein, Professor, Duke University

Host: Venkat Chandrasekhar