Quantum memory in the hard X-ray range: Storing and releasing X-ray pulses at the single photon level

https://phys.org/news/2024-08-quantum-memory-notoriously-difficult-ray.html

"imprinting information into quasi-stationary polarization/ spin wave with long coherence time, releasing it back via re-emission of original photons... much longer memory times using nuclear rather than atomic ensembles, even at high solid-state densities and room temperature... in combination with tight focusing of high-frequency photons enables long-lived broad-band compact solid-state quantum memories, intrinsically less noisy... moving nuclear absorbers forms frequency comb in absorption spectrum"