  A strange metal is an exotic state of correlated quantum matter; intensive
efforts are ongoing to decipher its nature. Here we explore whether the quantum
Fisher information (QFI), a concept from quantum metrology, can provide new
insight. We use inelastic neutron scattering and quantum Monte Carlo
simulations to study a Kondo destruction quantum critical point, where strange
metallicity is associated with fluctuations beyond a Landau order parameter. We
find that the QFI probed away from magnetic Bragg peaks, where the effect of
magnetic ordering is minimized, increases strongly and without a characteristic
scale as the strange metal forms with decreasing temperature, evidencing its
unusual entanglement properties. Our work opens a new direction for studies
across strange metal platforms.
