Abstract
We consider the nonequilibrium time evolution of piecewise homogeneous states in the spin- chain, a paradigmatic example of an interacting integrable model. The initial state can be thought of as the result of joining chains with different global properties. Through dephasing, at late times, the state becomes locally equivalent to a stationary state which explicitly depends on position and time. We propose a kinetic theory of elementary excitations and derive a continuity equation which fully characterizes the thermodynamics of the model. We restrict ourselves to the gapless phase and consider cases where the chains are prepared: (1) at different temperatures, (2) in the ground state of two different models, and (3) in the “domain wall” state. We find excellent agreement (any discrepancy is within the numerical error) between theoretical predictions and numerical simulations of time evolution based on time-evolving block decimation algorithms. As a corollary, we unveil an exact expression for the expectation values of the charge currents in a generic stationary state.
- Received 17 June 2016
DOI:https://doi.org/10.1103/PhysRevLett.117.207201
© 2016 American Physical Society
Physics Subject Headings (PhySH)
Viewpoint
A More Efficient Way to Describe Interacting Quantum Particles in 1D
Published 27 December 2016
A new method for calculating the time-evolving behavior of interacting quantum particles in one dimension can be used to model experiments that were previously beyond description.
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