A single photon is a light quanta, which can be dealt with a particle rather than a wave. We are interested in studying multi-photon quantum interference and quantum metrology using a quantum probe state such as multi-mode N00N states.
Quantum sensing using diamond NV centers
NV centers are point defects in diamond having unique properties for ultra-sensitive, high-resolution magnetometry. Extraordinarily long coherence times at room temperature of the NV center result in a high magnetic field resolution. In addition, because of the sub-nm small size of the NV center, it can be brought extremely close to a sample leading to a significant increase in the magnitude of the detected field. This high sensitivity combined with the high magnetic field resolution makes the NV center an ideal sensor to perform high-resolution nuclear magnetic resonance spectroscopy experiments at low field. Our goal is to use these NV centers for NMR at low magnetic fields of nano-size samples.
S. Hong et al., “Quantum enhanced multiple-phase estimation with multi-mode N00N states”, Nat. Commun. 12, 5211 (2021).