Microwave spectroscopy of Majorana vortex modes
Zhibo Ren1, Justin Copenhaver2, and Jukka Vayrynen1
1 Purdue University, West Lafayette, IN, USA
2 University of Colorado, Boulder, CO, USA
Majorana zero modes have been predicted to be hosted in vortices of certain iron-based topological superconductors. Recent observations of zero-bias conductance peaks in vortex cores of such superconductors have sparked renewed interest in vortex-bound Majorana states. However, progress toward a vortex-based topological qubit is hindered by our inability to measure the topological quantum state of a non-local vortex Majorana state, i.e., the charge of a vortex pair. Here, we theoretically propose a microwave-based charge parity readout of the Majorana vortex pair charge. We study the coupling between electrons in the iron-based superconductor and the photons from a microwave resonator above the superconductor. The frequency-dependent transmission of the resonator allows for a dispersive readout of the Majorana parity. Our technique may also be used in vortices in conventional superconductors and allows one to probe the lifetime of vortex-bound quasiparticles, which is currently beyond existing scanning tunneling microscopy capabilities.
This material is based upon work supported by the Office of the Under Secretary of Defense for Research and Engineering under award number FA9550-22-1-0354.