Strange metals and black holes: insights from the Sachdev-Ye-Kitaev model

Abstract: Complex many-particle quantum entanglement is a central theme in two distinct major topics in physics: the strange metal state found in numerous correlated electron compounds, and the quantum theory of black holes in Einstein gravity. The Sachdev-Ye-Kitaev model provides a solvable theory of entangled many-particle quantum states without quasiparticle excitations. This article reviews how this toy model has led to realistic universal models of strange metals, and to new insights on the quantum states of black holes.