arXiv:1005.2144 · Annalen der Physik

Entanglement in fermionic chains with interface defects

Viktor Eisler, Ingo Peschel

Published Jul 19, 2010• 79 citations

Abstract

Abstract We study the ground‐state entanglement of two halves of a critical transverse Ising chain, separated by an interface defect. From the relation to a two‐dimensional Ising model with a defect line we obtain an exact expression for the continuously varying effective central charge which governs the asymptotic behaviour of the entanglement entropy. The result is relevant also for other fermionic chains.

DOI: 10.1002/andp.201000055

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arXiv:1005.2144 · Annalen der Physik

Entanglement in fermionic chains with interface defects

Viktor Eisler, Ingo Peschel

Published Jul 19, 2010• 79 citations

arXiv HTML PDF

Abstract

DOI: 10.1002/andp.201000055

Related papers

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arXiv:1205.4331Europhysics Letters (EPL)Jul 1, 201282 citations

Entanglement entropy with localized and extended interface defects

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The quantum Ising chain of length,

L

, which is separated into two parts by localized or extended defects is considered at the critical point where scaling of the interface magnetization is nonuniversal. We measure the entanglement entropy between the two halves of the system in equilibrium, as well as after a quench, when the interaction at the interface is changed for time

t>0

. For the localized defect the increase in the entropy with

\text{log}\text{ }L

or with

\text{log}\text{ }t

involves the same effective central charge, which is a continuous function of the strength of the defect. On the contrary for the extended defect the equilibrium entropy is saturated but the nonequilibrium entropy has a logarithmic time dependence the prefactor of which depends on the strength of the defect.