Stanford Institute for Theoretical Physics presents "Replica wormhole and information retrieval in the SYK model coupled to Majorana chains"

Topic: 
Replica wormhole and information retrieval in the SYK model coupled to Majorana chains
Monday, April 20, 2020 - 2:00pm
Venue: 
Zoom id: 165-492-015
Speaker: 
Pengfei Zhang (Caltech)
Abstract / Description: 

Motivated by recent studies of the information paradox in (1+1)-D anti-de Sitter spacetime with a bath described by a (1+1)-D conformal field theory, we study the dynamics of second Rényi entropy of the Sachdev-Ye-Kitaev (SYK) model (χ) coupled to a Majorana chain bath (ψ). The system is prepared in the thermofield double (TFD) state and then evolved by HL+HR. For small system-bath coupling, we find that the second Rényi entropy S(2)χL,χR of the SYK model undergoes a first order transition during the evolution. In the sense of holographic duality, the long-time solution corresponds to a "replica wormhole". The transition time corresponds to the Page time of a black hole coupled to a thermal bath. We further study the information scrambling and retrieval by introducing a classical control bit, which controls whether or not we add a perturbation in the SYK system. The mutual information between the bath and the control bit shows a positive jump at the Page time, indicating that the entanglement wedge of the bath includes an island in the holographic bulk.