Entanglement evolution across a conformal interface

Xueda Wen, Yuxuan Wang, Shinsei Ryu

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13 Scopus citations


For two-dimensional conformal field theories (CFTs) in the ground state, it is known that a conformal interface along the entanglement cut can suppress the entanglement entropy from SA ∼ c log L to SA∼ ceff log L, where L is the length of the subsystem A, and ceff ∈ [0, c] is the effective central charge which depends on the transmission property of the conformal interface. In this work, by making use of conformal mappings, we show that a conformal interface has the same effect on entanglement evolution in non-equilibrium cases, including global, local and certain inhomogeneous quantum quenches. I.e. a conformal interface suppresses the time evolution of entanglement entropy by effectively replacing the central charge c with ceff, where ceff is exactly the same as that in the ground state case. We confirm this conclusion by a numerical study on a critical fermion chain. Furthermore, based on the quasi-particle picture, we conjecture that this conclusion holds for an arbitrary quantum quench in CFTs, as long as the initial state can be described by a regularized conformal boundary state.

Original languageEnglish (US)
Article number195004
JournalJournal of Physics A: Mathematical and Theoretical
Issue number19
StatePublished - Apr 17 2018
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Statistical and Nonlinear Physics
  • Statistics and Probability
  • Modeling and Simulation
  • Mathematical Physics
  • General Physics and Astronomy


  • conformal field theory
  • quantum entanglement
  • quantum quench


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