Theoretical physicists along with an experimental team have found evidence of a quantum spin liquid in a material known as pyrochlore cerium stannate. They achieved this by combining state-of-the-art experimental techniques, including neutron scattering at extremely low temperatures, with theoretical analysis. By measuring the way in which neutrons interact magnetically with the electron spin in pyrochlore, the researchers observed the collective excitations of spins interacting strongly with light-like waves.