Boundary effects on quantum entanglement and its dynamics in a detector-field system

Rong Zhou, Ryan O. Behunin, Shih Yuin Lin, B. L. Hu

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


In this paper we analyze an exactly solvable model consisting of an inertial Unruh-DeWitt detector which interacts linearly with a massless quantum field in Minkowski spacetime with a perfectly reflecting flat plane boundary. Firstly a set of coupled equations for the detector's and the field's Heisenberg operators are derived. Then we introduce the linear entropy as a measure of entanglement between the detector and the quantum field under mirror reflection, and solve the early-time detector-field entanglement dynamics. After coarse-graining the field, the dynamics of the detector's internal degree of freedom is described by a quantum Langevin equation, where the dissipation and noise kernels respectively correspond to the retarded Green's functions and Hadamard elementary functions of the free quantum field in a half space. At late times when the combined system is in a stationary state, we obtain exact expressions for the detector's covariance matrix and show that the detector-field entanglement decreases for smaller separation between the detector and the mirror. We explain the behavior of detector-field entanglement qualitatively with the help of a detector's mirror image, compare them with the case of two real detectors and explain the differences.

Original languageEnglish (US)
Article number40
JournalJournal of High Energy Physics
Issue number8
StatePublished - 2013
Externally publishedYes


  • Boundary Quantum Field Theory
  • Quantum Dissipative Systems

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


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