2011/06/30 by Tomaz Prosen · 1 citation
Physics and Astronomy · #quant-ph #cond-mat.stat-mech #cond-mat.str-el #nlin.SI
paper · pdf · doi:10.1103/physrevlett.107.137201
published as Phys. Rev. Lett. 107, 137201 (2011) · 5 REVTeX pages; minor corrections + fig.2 added, essentially equivalent to the published version
arxiv created 2011/09/19 · arxiv updated 2015/05/28
An exact and explicit ladder-tensor-network ansatz is presented for the non-equilibrium steady state of an anisotropic Heisenberg XXZ spin-1/2 chain which is driven far from equilibrium with a pair of Lindblad operators acting on the edges of the chain only. We show that the steady-state density operator of a finite system of size n is - apart from a normalization constant - a polynomial of degree 2n-2 in the coupling constant. Efficient computation of physical observables is faciliated in terms of a transfer operator reminiscent of a classical Markov process. In the isotropic case we find cosine spin profiles, 1/n2 scaling of the spin current, and long-range correlations in the steady state. This is a fully nonperturbative extension of a recent result [Phys. Rev. Lett. 106, 217206 (2011)].