Year: 1993
Type: article
Abstract: The repartition of the separation between energy levels of various isotropic S=1/2 antiferromagnetic chains is studied numerically with the aim of investigating the transition from integrable to noninte- grable systems. We begin by displaying the level separation distribution of the integrable Bethe chain. Then two nonintegrable systems, two coupled chains, and a next-nearest-neighbor coupled chain, are studied as a function of the coupling. We examine how the level spacing evolves from the Poisson distribution to the Gaussian-orthogonal-ensemble distribution. Finally we consider the Haldane-Shastry 1/${\mathit{r}}^{2}$ model. A number of conclusions regarding the behavior and relevance of the level-spacing distribution in these spin systems is drawn.
Authors: Theodore C. Hsu, J. C. Angle`s d’Auriac
Language: English
Topic: Quantum many-body systems
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2018335989