Time evolution of entanglement negativity across a defect

Matthias Gruber*, Viktor Eisler

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


We consider a quench in a free-fermion chain by joining two homogeneous half-chains via a defect. The time evolution of the entanglement negativity is studied between adjacent segments surrounding the defect. In case of equal initial fillings, the negativity grows logarithmically in time and essentially equals one-half of the Rényi mutual information with index α = 1/2 in the limit of large segments. In sharp contrast, in the biased case one finds a linear increase followed by the saturation at an extensive value for both quantities, which is due to the backscattering from the defect and can be reproduced in a quasiparticle picture. Furthermore, a closer inspection of the subleading corrections reveals that the negativity and the mutual information have a small but finite difference in the steady state. Finally, we also study a similar quench in the XXZ spin chain via density-matrix renormalization group methods and compare the results for the negativity to the fermionic case.
Original languageEnglish
Article number205301
Number of pages27
JournalJournal of Physics A: Mathematical and Theoretical
Issue number20
Publication statusPublished - 28 Apr 2020


  • classical model
  • Quantum adiabatic algorithms
  • shortcuts to adiabaticity

ASJC Scopus subject areas

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


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