High-temperature coherent transport in the XXZ chain in the presence of an impurity

Marlon Brenes, Eduardo Mascarenhas, Marcos Rigol, John Goold

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

We study high-temperature spin transport through an anisotropic spin-12 Heisenberg chain in which integrability is broken by a single impurity close to the center of the chain. For a finite impurity strength, the level spacing statistics of this model is known to be Wigner-Dyson. Our aim is to understand if this integrability breaking is manifested in the high-temperature spin transport. We focus first on the nonequilibrium steady state (NESS), where the chain is connected to spin baths that act as sources and sinks for spin excitations at the boundaries. Using a combination of open quantum system theory and matrix product operators techniques, we extract the transport properties by means of a finite-size scaling of the spin current in the NESS. Our results indicate that, despite the formation of a partial domain wall in the steady state magnetization (and despite the Wigner-Dyson level spacing distribution of the model), transport remains ballistic. We contrast this behavior with the one produced by a staggered magnetic field in the XXZ chain, for which it is known that transport is diffusive. By performing a numerical computation of the real part of the spin conductivity, we show that our findings are consistent with linear response theory. We discuss subtleties associated with the apparent vanishing of the Drude in the presence of an impurity.

Original languageEnglish (US)
Article number235128
JournalPhysical Review B
Volume98
Issue number23
DOIs
StatePublished - Dec 12 2018

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Impurities
impurities
Domain walls
System theory
Ballistics
Transport properties
Temperature
Magnetization
Statistics
Magnetic fields
spacing
sinks
ballistics
domain wall
baths
transport properties
statistics
scaling
operators
conductivity

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

Brenes, Marlon ; Mascarenhas, Eduardo ; Rigol, Marcos ; Goold, John. / High-temperature coherent transport in the XXZ chain in the presence of an impurity. In: Physical Review B. 2018 ; Vol. 98, No. 23.
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High-temperature coherent transport in the XXZ chain in the presence of an impurity. / Brenes, Marlon; Mascarenhas, Eduardo; Rigol, Marcos; Goold, John.

In: Physical Review B, Vol. 98, No. 23, 235128, 12.12.2018.

Research output: Contribution to journalArticle

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