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arXiv · 1507.02993

Complete Generalized Gibbs Ensemble in an interacting Theory

Enej Ilievski·Jacopo De Nardis·Bram Wouters·Jean-Sebastien Caux·Fabian H. L. Essler·Tomaz Prosen
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Abstract

In integrable many-particle systems, it is widely believed that the stationary state reached at late times after a quantum quench can be described by a generalized Gibbs ensemble (GGE) constructed from their extensive number of conserved charges. A crucial issue is then to identify a complete set of these charges, enabling the GGE to provide exact steady state predictions. Here we solve this long-standing problem for the case of the spin-1/2 Heisenberg chain by explicitly constructing a GGE which uniquely fixes the macrostate describing the stationary behaviour after a general quantum quench. A crucial ingredient in our method, which readily generalizes to other integrable models, are recently discovered quasi-local charges. As a test, we reproduce the exact post-quench steady state of the Neel quench problem obtained previously by means of the Quench Action method.

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Enej Ilievski, Jacopo De Nardis, Bram Wouters, Jean-Sebastien Caux, Fabian H. L. Essler, Tomaz Prosen. 2015-08-25. Complete Generalized Gibbs Ensemble in an interacting Theory. https://doi.org/10.1103/physrevlett.115.157201

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