| （英） |
Although the existence of dark matter is strongly supported by cosmological observations, its particle physics nature is unknown due to the lack of direct detection. The main difficulties in detection are the small couplings to standard model particles and the extremely wide search range. One of the most promising candidates for light dark matter is the axion, which was predicted as a solution to the strong CP problem in particle physics. Cosmology suggests axions can have a microelectron-volts mass, corresponding Compton frequency of in the GHz range. The particle physics community has been searching for axions for more than a half century but has yet to discover them. The most sensitive existing experiments use quantum amplifiers, but the sensitivity of the search is limited by vacuum fluctuations. Therefore, an ultra-sensitive electromagnetic field sensor is needed. Superconducting qubits often operate in the GHz frequency range which equivalent to the predicted axion energy range, have a large electric dipole moment, and have extremely low thermal noise. We have been proposing experimental principles, fabricating superconducting qubits, and conducting actual experiments for dark matter searches using qubits. In this talk, the status and prospects of several dark matter search experiments using superconducting qubits will be presented. |