The Link between Integrability, Level Crossings, and Exact Solution in Quantum Models

التفاصيل البيبلوغرافية
العنوان: The Link between Integrability, Level Crossings, and Exact Solution in Quantum Models
المؤلفون: Owusu, H. K., Wagh, K., Yuzbashyan, E. A.
المصدر: 2009 J. Phys. A: Math. Theor. 42 035206
سنة النشر: 2008
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Statistical Mechanics
الوصف: We investigate the connection between energy level crossings in integrable systems and their integrability, i.e. the existence of a set of non-trivial integrals of motion. In particular, we consider a general quantum Hamiltonian linear in the coupling u, H(u) = T + uV, and require that it has the maximum possible number of nontrivial commuting partners also linear in u. We demonstrate how this commutation requirement alone leads to: (1) an exact solution for the energy spectrum and (2) level crossings, which are always present in these Hamiltonians in violation of the Wigner-von Neumann non-crossing rule. Moreover, we construct these Hamiltonians explicitly by resolving the above commutation requirement and show their equivalence to a sector of Gaudin magnets (central spin Hamiltonians). In contrast, fewer than the maximum number of conservation laws does not guarantee level crossings.
Comment: 33 pages, 10 figures, minor typos corrected, reference added, model generalized beyond real symmetric to Hermitian operators
نوع الوثيقة: Working Paper
DOI: 10.1088/1751-8113/42/3/035206
URL الوصول: http://arxiv.org/abs/0807.0259
رقم الأكسشن: edsarx.0807.0259
قاعدة البيانات: arXiv
الوصف
DOI:10.1088/1751-8113/42/3/035206