LAUSR

Significance The strange metal state of the cuprate superconductors is the parent state from which many novel quantum phases emerge. Experiments have shown that the strange metal extends over a wider range of electron densities than previously believed. We show that a dynamic mean-field theory with random exchange interactions, in which the electron fractionalizes into excitations carrying its spin and charge, displays an extended strange metal regime. Several physical properties of this strange metal are in accord with experimental observations, including a linear-in-temperature contribution to the resistivity. At lower carrier density, our theory displays an instability to a spin glass, which is also observed. Our mean-field theory shows a route toward theories of quantum materials based upon more realistic microscopic models.