Or
Katz
Katz, O. ., Reches, E. ., Shaham, R. ., Gorshkov, A. V., & Firstenberg, O. . (2020). Optical quantum memory with optically inaccessible noble-gas spins. ArXiv:2007.08770. Retrieved from https://arxiv.org/abs/2007.08770 (Original work published July 2020)