Entanglement spreading after local and extended excitations in a free-fermion chain

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We study the time evolution of entanglement created by local or extended excitations upon the ground state of a free-fermion chain. A single particle or hole excitation produces a single bit of excess entropy for large times and subsystem lengths. In case of a double hole, some of the coherence between the excitations is preserved and the excess entropy becomes additive only for large hole separations. In contrast, the coherence is always lost for particle-hole excitations. Multiple hole excitations on a completely filled chain are also investigated. We find that for an extended contiguous hole the excess entropy scales logarithmically with the size, whereas the increase is linear for finite separations between the holes.
Original languageEnglish
Article number424002
JournalJournal of Physics A: Mathematical and Theoretical
Issue number42
Publication statusPublished - 22 Oct 2021


  • cond-mat.stat-mech
  • quant-ph
  • entanglement
  • free-fermion chain
  • excitations

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Statistical and Nonlinear Physics
  • Statistics and Probability
  • Mathematical Physics
  • Modelling and Simulation

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