We gratefully acknowledge support from
the Simons Foundation and member institutions.
Full-text links:


Current browse context:

new | recent | 1502

Change to browse by:

References & Citations

Condensed Matter > Strongly Correlated Electrons

Title:Thermalization away from Integrability and the Role of Operator Off-Diagonal Elements

Abstract: We investigate the rate of thermalization of local operators in the one-dimensional anisotropic antiferromagnetic Heisenberg model with next-nearest neighbor interactions that break integrability. This is done by calculating the scaling of the difference of the diagonal and canonical thermal ensemble values as function of system size, and by directly calculating the time evolution of the expectation values of the operators with the Chebyshev polynomial expansion. Spatial and spin symmetry is exploited and the Hamiltonian is divided in subsectors according to their symmetry. The rate of thermalization depends on the proximity to the integrable limit. When integrability is weakly broken thermalization is slow, and becomes faster the stronger the next-nearest neighbor interaction is. Three different regimes for the rate of thermalization with respect to the strength of the integrability breaking parameter are identified. These are shown to be directly connected with the relative strength of the low and higher energy difference off-diagonal operator matrix elements in the symmetry eigenbasis of the Hamiltonian. Close to the integrable limit the off-diagonal matrix elements peak at higher energies and high frequency fluctuations are important and slow down thermalization. Away from the integrable limit a strong low energy peak gradually develops that takes over the higher frequency fluctuations and leads to quicker thermalization.
Comments: 11 pages, 9 figures
Subjects: Strongly Correlated Electrons (cond-mat.str-el)
DOI: 10.1103/PhysRevE.91.052111
Cite as: arXiv:1502.06320 [cond-mat.str-el]
  (or arXiv:1502.06320v1 [cond-mat.str-el] for this version)

Submission history

From: Nikolaos P. Konstantinidis [view email]
[v1] Mon, 23 Feb 2015 05:47:13 UTC (120 KB)