An international team of scientists including Roderich Moessner of the Max Planck Institute for the Physics of Complex Systems has observed an exotic quantum state of matter: a spin-orbital liquid formed on the pyrochlore oxide Pr2
. Here, both spin and orbital degrees of freedom remain dynamic down to extremely low temperature. It is known from the long history of condensed matter physics that suppressing orbital order down to low temperatures is extremely difficult, a precondition for the next tricky step of obtaining a spin-orbital liquid state. Pr2
serves as a rare counterexample in which spins and orbitals are interlocked, so that fluctuation of one necessitates fluctuation of the other. More details can be found in a press release (PDF)
N. Tang, Y. Grisenko, K. Kimura et al.
, Nat. Phys. (2022)
See also the related Nat. Phys. News & Views article
by V. S. Zapf, M. Lee, and P. F. S. Rosa.