Chiral Spin-Chain Interfaces Exhibiting Event-Horizon Physics

The interface between different quantum phases of matter can give rise to novel physics, such as exotic topological phases or nonunitary conformal field theories. Here we investigate the interface between two spin chains in different chiral phases. Surprisingly, the mean field theory approximation of this interacting composite system is given in terms of Dirac fermions in a curved space-time geometry. In particular, the interface between the two phases represents a black hole horizon. We demonstrate that this representation is faithful both analytically, by employing bosonization to obtain a Luttinger liquid model, and numerically, by employing matrix product state methods. A striking prediction from the black hole equivalence emerges when a quench, at one side of the interface between two opposite chiralities, causes the other side to thermalize with the Hawking temperature for a wide range of parameters and initial conditions.

Automated summary

The interface between different quantum phases of matter can lead to new physics, such as exotic topological phases or nonunitary conformal field theories. This study explores the interface between two spin chains in different chiral phases. Surprisingly, the mean field theory approximation of this interacting composite system can be described using Dirac fermions in a curved space-time geometry. The interface between the two phases represents a black hole horizon. Analytical and numerical methods confirm this representation, and a striking prediction emerges regarding thermalization at the interface.