Researchers Find Dark States Boost Spin-Ensemble Memory

Researchers at Walther-Meißner-Institut, in collaboration with University of Augsburg, Technical University of Munich, and Munich Center for Quantum Science and Technology (MCQST), demonstrate controlled coupling between multiple superconducting microwave cavities and a spin ensemble. This work reveals signatures of strong coupling and the formation of dark states, features which could substantially improve quantum memory times and facilitate the protected storage of non-classical states within spin ensembles by reducing interaction with the surrounding circuit environment. By modelling the resulting spin-multi-cavity hybrid system and employing input-output formalism, the team successfully reproduces observed spectra and…