Abstract
We investigate the influence of different interaction strengths and dimerizations on the magnetization transport in antiferromagnetic spin chains. We focus on the real-time evolution of the inhomogeneous initial state in using the adaptive time-dependent density-matrix renormalization group (adaptive t-DMRG). Time scales accessible to us are of the order of 100 units of time measured in for almost negligible error in the observables. We find ballistic magnetization transport for small interaction and arbitrary dimerization, but almost no transport for stronger interaction, with a sharp crossover at . Additionally, we perform a detailed analysis of the error made by the adaptive time-dependent DMRG using the fact that the evolution in the model is known exactly. We find that the error at small times is dominated by the error made by the Trotter decomposition, whereas for longer times the DMRG truncation error becomes the most important, with a very sharp crossover at some “runaway” time. Overall, errors are extremely small before the “runaway” time.
13 More- Received 7 October 2004
DOI:https://doi.org/10.1103/PhysRevE.71.036102
©2005 American Physical Society