Absorption peaks in topological phase transition of planar Josephson junctions*

Planar Josephson junctions provide an attractive platform to experimentally realize topological superconductivity [1,2]. We consider a planar Josephson junction inductively coupled to a microwave circuit QED system and investigate the effects of topological transitions on the microwave absorption spectra. The microwave field induces ac phase fluctuations across the junction, which drive transitions between the Andreev levels in the microwave range [3,4]. The planar Josephson junction is in topological class D and thus can support Majorana states at the ends of the junction [5,6]. Tight-binding simulations of the system show sudden change in the absorption characteristics of the system as a system parameter is changed to induce topological transitions.

Funding Acknowledgment:

U.S. ONR Grants No. N000141712793 and MURI No. N000142212764.