Witness Spins Transition to Spin Glass Phase at 260 Millikelvin

Researchers have observed a sharp transition in the magnetic behavior of herbertsmithite at around 260 mK, a temperature at which impurity atoms within the material coalesce into a spin glass phase. These impurities, created by approximately 33% substituted copper atoms on zinc sites, were reconsidered as a tool to probe the material's elusive quantum spin liquid state, a state theorized to host quasiparticles called spinons. Instead, the team utilized spin noise spectroscopy to measure the dynamics of these witness spins, revealing interactions mediated by these spinons and establishing a direct link between theoretical particles and observable dynamics. The researchers explain that in the theory of such materials, strongly interacting…