The JCMS series

The Joint Condensed Matter Seminar (JCMS) series is organised by KTH Royal Insitute of Technology, Nordita, and Stockholm University.

January 12th, 2023: Felix von Oppen

On Thursday, January 12th, 2023 from 13 to 14 we will host a seminar by Felix von Oppen from Freie Universität Berlin.

Title

Diode effects in current-biased Josephson junctions

Abstract

Current flow in electronic devices can be asymmetric with bias direction, a phenomenon underlying the utility of diodes and known as non-reciprocal charge transport. The promise of dissipationless electronics has recently stimulated the quest for superconducting diodes. Non-reciprocal Josephson junctions are particularly promising for device applications, for instance in the context of superconducting qubits. In this talk, I will discuss a recent experiment, in which non-reciprocity is observed as the result of introducing a single magnetic atom into the Josephson junction and use this as a starting point for developing a general theory of non-reciprocal transport in current-biased Josephson junctions. This will include a discussion of the symmetry requirements underlying non-reciprocal transport. I will also briefly describe a generalized derivation of the Keldysh action of Josephson junctions, which incorporates non-reciprocity.