Microwave induced single electron transitions between zero modes in hybrid superconducting-semiconducting islands
D. Sabonis, D. van Zanten, J. Sutter, E. O’Farrell, D. Razmadze, K. Petersson, P. Krogstrup, C. M. Marcus
Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
Superconductor-semiconductor structures can be driven into a topological regime by application of an external magnetic field, in which Majorana zero modes emerge. Our contribution extends previous work on Majorana modes in superconducting structures [1-5], by developing nanowire-based double-island devices where both the Josephson coupling as well as Majorana coupling between islands can be manipulated using gate electrodes, whereas the charge of islands can be measured with high-bandwidth proximal charge sensors (Fig. 1).
We experimentally study microwave induced transitions between two superconducting islands when the magnetic field along the nanowire axis is applied. At higher magnetic fields we observe a change in gate space periodicity of the microwave induced transitions. Results are compatible with single electron transitions between zero modes on both sides of the junction. From microwave spectroscopy extracted energy scales for Josephson and single electron coupling will be useful in the near future experiments.
Research supported by Microsoft Project Q and the Danish National Research Foundation.
References
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