Circuit-QED characterization of a topological Josephson junction

Description

The search for topological superconductivity in topological insulator (TI) nanowires have attracted a lot of interest due to potential applications in the field of topologically protected quantum computation [1-3]. One route to emulate unconventional superconductivity is to build a topological Josephson junction from a TI nanowire (Bi2Se3) connected to two conventional superconducting electrodes (Al). Such topological Josephson junctions are expected to host Majorana zero-energy modes (bound states) when they are phase-biased at pi. The bound state spectrum of a junction hosting several transport modes consists of topological trivial Andreev bound states and topologically protected Majorana bound states. The phase dependence of those bound states has been studied experimentally using a circuit-QED-like setup, where the topological junction is embedded in a superconducting resonator. Here the frequency response of the coupled resonator/junction system to an externally applied magnetic field (phase bias) at various temperatures is used to deduce information about the phase dependence of the bound state spectrum of the junction. I detail, the contributions to the junction dissipation (which is directly reflected in the inverse quality factor of the coupled resonator/junction system) originating from zero-energy bound states and topological trivial Andreev bound states are rather distinct, which is mainly reflected in their phase bias dependence around and their evolution in temperature.

Resources

Name Format Description Link
0 http://data.europa.eu/88u/dataset/oai-zenodo-org-5799445
0 http://data.europa.eu/88u/dataset/oai-zenodo-org-5799445

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