Roy’s paper “Phase dependent microwave response of a graphene Josephson junction” is now out. See Phys. Rev. Research 4, 013198 (2022). Roy shows that one can obtain both the resistive the resistive loss and the critical current from GHz reflectometry measurements. It is intriguing to see that the gap of a graphene Josephson weak link is virtually fully filled with Andreev bound states at phase π. This leads to a pronounced dissipation at this phase bias. 

A full dataset starting with the measured phase-dependent frequency shift converted to supercurrent (the two colored images on the top left). The four plots in the right upper corner show three cuts of the frequency shift and supercurrent. At the bottom the gate-dependence of the first four Fourier coefficients of the non-sinusoidal current-phase relation to the supercurrent are shown.

 

a note from Christian during an internal discussion meeting
Congratulation Roy: seminal paper out
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