Black Hole States in Quantum Spin Chains

We define a black hole state in a spin chain by studying thermal correlators in holography. Focusing on the Heisenberg model we investigate the thermal and complexity properties of the black hole state by evaluating its entanglement entropy, emptiness formation probability, and Krylov complexity. The entanglement entropy grows logarithmically with effective central charge c≃5.2. We also find evidence for thermalization at infinite temperature.