The reflected entanglement spectrum for free fermions

Souvik Dutta, Thomas Faulkner, Simon Lin

Research output: Contribution to journalArticlepeer-review


We consider the reflected entropy and the associated entanglement spectrum for free fermions reduced to two intervals in 1 + 1 dimensions. Working directly in the continuum theory the reflected entropy can be extracted from the spectrum of a singular integral equation whose kernel is determined by the known free fermion modular evolved correlation function. We find the spectrum numerically and analytically in certain limits. For intervals that almost touch the reflected entanglement spectrum approaches the spectrum of the thermal density matrix. This suggests that the reflected entanglement spectrum is well suited to the task of extracting physical data of the theory directly from the ground state wave function.

Original languageEnglish (US)
Article number223
JournalJournal of High Energy Physics
Issue number2
StatePublished - Feb 2023


  • Field Theories in Lower Dimensions
  • Scale and Conformal Symmetries

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


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