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Microwave Sensing of Andreev Bound States in a Gate-Defined Superconducting Quantum Point Contact
- Source :
- Phys. Rev. Research 4, 023170 (2022)
- Publication Year :
- 2021
-
Abstract
- We use a superconducting microresonator as a cavity to sense absorption of microwaves by a superconducting quantum point contact defined by surface gates over a proximitized two-dimensional electron gas. Renormalization of the cavity frequency with phase difference across the point contact is consistent with adiabatic coupling to Andreev bound states. Near $\pi$ phase difference, we observe random fluctuations in absorption with gate voltage, related to quantum interference-induced modulations in the electron transmission. We identify features consistent with the presence of single Andreev bound states and describe the Andreev-cavity interaction using a dispersive Jaynes-Cummings model. By fitting the weak Andreev-cavity coupling, we extract ~GHz decoherence consistent with charge noise and the transmission dispersion associated with a localized state.
Details
- Database :
- arXiv
- Journal :
- Phys. Rev. Research 4, 023170 (2022)
- Publication Type :
- Report
- Accession number :
- edsarx.2102.05206
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1103/PhysRevResearch.4.023170