Coherent coupling of spinning light and NV centers in diamond

Coherent coupling between optical fields and solid-state spins is essential for building a spin–photon interface and exchanging quantum information. The nitrogen-vacancy (NV) center, a solid-state defect center in diamond, is a promising qubit system for its relatively high-temperature spin coherence. Here, we study the coherent coupling between the photonic spin texture (PST) and the quantum polarization cloud (phase shift) of NV centers spanning a temperature range from liquid nitrogen (77 K) to room temperature (295 K). We show that by optimizing the laser power and frequency detuning, it is possible to maintain coherence in NV–photon interaction even in this nonideal limit. The coherent NV–photon interaction in our experiment is encoded in the quantum phase shift of the NV center spin qubit, which can be read out using the Hahn-echo magnetometry technique. Our approach of studying light–matter interaction at an elevated temperature can build an unexplored regime of spin–photon interface, which has potential applications in diverse quantum applications.