Probing coherent coupling of Majorana modes via single-electron photon assisted tunneling: Part 1*

The coherent coupling between Majorana zero modes localized in distinct topological islands mixes the 1e charge states of islands. This coherent superposition of even and odd parity states is a necessary condition for the operation of topological qubits. We demonstrate the coherent coupling of zero modes in a superconducting double island created in a InAs/Al nanowire. This is achieved by tracking microwave induced charge transitions between the islands. The dispersion of photon assisted tunneling features is 1e periodic and shows the presence of an anti-crossing between even and odd parity charge states.
In this talk we will first characterize the coupling between islands using microwave spectroscopy in the absence of magnetic field and finally discuss the transition into the topological regime.