Speaker
Description
Using superconducting qubits for dark matter detection has been drawing a lot of attention recently. Since some ultra-light dark matter, such as axions and dark photons, is theoretically predicted to convert to ordinary photons whose frequency is around GHz, weak photon sensing techniques with qubits can be used. Besides, such dark matter sensing is performed in a dilution refrigerator to avoid thermal noise, for the same reason in quantum technology. For example, superconducting qubits are used as sensors themselves [1,2,3], or cavity frequency tuners [4,5].
In terms of using a cavity-qubit hybrid system, stronger coupling between them is one of the efficient ways to utilize cavity-qubit interaction. In this poster, I would like to introduce a galvanically contacted cavity-qubit hybrid system. Contacting the wall of three-dimensional cavity and the pads of superconducting qubits with indium bumping, realizes the strongest coupling which couldn’t be realized with capacitive coupling.
In this poster session, I will talk about the simulations of this hybrid system, the implementation status, and future prospects for dark matter sensing.
[1] A. V. Dixit, et al., Phys. Rev. Lett. 126, 141302 (2021).
[2] S. Chen, et al., Phys. Rev. Lett. 131, 211001 (2023).
[3] C. Braggio, et al., Phys. Rev. X 15, 021031 (2025).
[4] F. Zhao, et al., Phys. Rev. Lett. 135, 201002 (2025).
[5] K. Nakazono et al., arXiv:2505.15619 (2025).