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arXiv · 1103.1350

Open XXZ spin chain: Nonequilibrium steady state and strict bound on ballistic transport

Tomaz Prosen
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Abstract

Explicit matrix product ansatz is presented, in first two orders in the (weak) coupling parameter, for the non-equilibrium steady state of the homogeneous, nearest neighbor Heisenberg XXZ spin-1/2 chain driven by Lindblad operators which act only at the edges of the chain. The first order of the density operator becomes in thermodynamic limit an exact pseudo-local conservation law and yields -- via Mazur inequality -- a rigorous lower bound on the high temperature spin Drude weight. Such Mazur bound is a non-vanishing fractal function of the anisotropy parameter Delta for |Delta|<1.

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Tomaz Prosen. 2011-05-27. Open XXZ spin chain: Nonequilibrium steady state and strict bound on ballistic transport. https://doi.org/10.1103/physrevlett.106.217206

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