Robust mode conversion in NV centers using exceptional points

Abstract

We show that microwave-driven NV centers can function as robust mode switches by utilizing a special degeneracy called an exceptional point (EP). While previous theoretical and experimental work on EP-based mode switches applies only to pure states, we develop here a general theory for switching between mixed states, statistical ensembles of different pure states, resulting from the interaction with the environment. Our theory is general and applicable to all leading platforms for quantum information processing and quantum technologies. However, our numerical simulations use empirical parameters of NV centers. We provide guidelines for coping with the main challenges for experimental realization of this protocol: decoherence and mixed-state preparation.