Phase-matching of multiple-cavity detectors for dark matter axion search

Understand

Conventional axion dark matter search experiments employ cylindrical microwave cavities immersed in a solenoidal magnetic field.

• Exploring higher frequency regions requires smaller size cavities as the TM010 resonant frequencies scale inversely with cavity radius.
• One intuitive way to make efficient use of a given magnet volume, and thereby to increase the experimental sensitivity, is to bundle multiple cavities together and combine their individual outputs ensuring phase-matching of the coherent axion signal.
• We perform an extensive study for realistic design of a phase-matching mechanism for multiple-cavity systems and demonstrate its experimental feasibility using a double-cavity system.