Microwave signatures of Majorana states in a topological Josephson junction

Year: 2015

Authors: Vdyrynen J.I., Rastelli G., Belzig W., Glazman L.I.

Autors Affiliation: Yale Univ, Dept Phys, New Haven, CT 06520 USA; Univ Konstanz, Zukunftskolleg, D-78457 Constance, Germany; Univ Konstanz, Fachbereich Phys, D-78457 Constance, Germany

Abstract: We find the admittance of a topological Josephson junction Y (omega, phi(0), T) as a function of frequency omega, the static phase bias phi(0) applied to the superconducting leads, and temperature T. The dissipative part of Y allows for spectroscopy of the subgap states in the junction. The resonant frequencies omega(M,n) (phi(0)) for transitions involving the Majorana (M) doublet exhibit characteristic kinks in the phi(0) dependence at phi(0) = pi. The kinks, associated with decoupled Majorana states, remain sharp and the corresponding spectroscopic lines are bright at any temperature, as long as the leads are superconducting. The developed theory may help with regard to extracting quantitative information about Majorana states from microwave spectroscopy.


Volume: 92 (13)      Pages from: 134508  to:

More Information: We thank Michel Devoret and Liang Fu for discussions, and Richard Brierley and Hendrik Meier for valuable comments on the manuscript. This work was supported by NSF DMR Grant No. 1206612, ONR Grant No. Q00704, ARO Grant No. W911NF-09-1-0514, the DFG through SFB 767, the EU FP7 Marie Curie Zukunftskolleg Incoming Fellowship Programme (Grant No. 291784), and a Senior Fellowship of the Zukunftskolleg, Konstanz.
KeyWords: Majorana states, Topological Josephson junctions
DOI: 10.1103/PhysRevB.92.134508