Non-ergodic states induced by impurity levels in quantum spin chains
| Autor: | Graciela. Cabrera., A. O. García Rodríguez |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Physics
Statistical Mechanics (cond-mat.stat-mech) Condensed matter physics Continuum (measurement) Time evolution FOS: Physical sciences General Physics and Astronomy Parameter space 01 natural sciences 010305 fluids & plasmas Magnetization Impurity 0103 physical sciences Thermodynamic limit Ergodic theory General Materials Science Physical and Theoretical Chemistry 010306 general physics Condensed Matter - Statistical Mechanics Eigenvalues and eigenvectors |
| Zdroj: | The European Physical Journal Special Topics. 227:301-311 |
| ISSN: | 1951-6401 1951-6355 |
| Popis: | The semi-infinite XY spin chain with an impurity at the boundary has been chosen as a prototype of interacting many-body systems to test for non-ergodic behavior. The model is exactly solvable in analytic way in the thermodynamic limit, where energy eigenstates and the spectrum are obtained in closed form. In addition of a continuous band, localized states may split off from the continuum, for some values of the impurity parameters. In the next step, after the preparation of an arbitrary non-equilibrium state, we observe the time evolution of the site magnetization. Relaxation properties are described by the long-time behavior, which is estimated using the stationary phase method. Absence of localized states defines an ergodic region in parameter space, where the system relaxes to a homogeneous magnetization. Out of this region, impurity levels split from the band, and localization phenomena may lead to non-ergodicity. 10 pages, 5 figures. arXiv admin note: substantial text overlap with arXiv:1703.03446 |
| Databáze: | OpenAIRE |
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