Light trapped inside a crystal has extended the memory of a quantum bit by a factor of one thousand.
Quantum information is incredibly fragile and usually disappears in just a few millionths of a second. This study achieved all-to-all interactions in a solid crystal that protected the information for much longer. The coherence time jumped from microseconds to milliseconds without needing any complex external pulses. This was done by using a cavity to protect the spins from their noisy environment. This breakthrough makes it much easier to build quantum hardware that can actually store and process data reliably.
Cavity-mediated coherence protection and one-axis twisting for spins in solids
arXiv · 2604.26909
Long-range interactions between emitters give rise to collective phenomena, including superradiance, spin squeezing, and coherence protection, that are important to both fundamental physics and quantum technologies. Despite progress in cold atoms, coherent cavity-mediated all-to-all interactions have not yet been realized in a solid-state ensemble. Here we demonstrate such interactions in a $^{171}$Yb$^{3+}$:CaWO$_4$ crystal coupled to a microwave resonator, observing superradiant emission on re