On the Spectrum of the XXZ-chain at roots of unity
| dc.creator | Braak, D. | |
| dc.creator | Andrei, N. | |
| dc.date | 2001-06-28 | |
| dc.date.accessioned | 2026-07-07T02:41:55Z | |
| dc.date.available | 2026-07-07T02:41:55Z | |
| dc.description | In a recent paper (cond-mat/0009279), Fabricius and McCoy studied the spectrum of the spin 1/2 XXZ-model at Delta = (q+q^{-1})/2 and q^{2N}=1 for integer N >1. They found a certain pattern of degeneracies and linked it to the sl(2)-loop symmetry present in the commensurable spin sector (N divides S^z). We show that the degeneracies are due to zero-energy, transparent excitations, the cyclic bound states. These exist both in commensurable and incommensurable sectors, indicating a symmetry, of which sl(2)-loop is a partial manifestation. Our approach treats both sectors on even footing and yields an analytical expression for the degeneracies in the case N = 3. | |
| dc.description | 27 pages | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0106593 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0106593 | |
| dc.identifier | J.Stat.Phys. 105, pp.677-709 (2001) | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/17939 | |
| dc.subject | Statistical Mechanics | |
| dc.title | On the Spectrum of the XXZ-chain at roots of unity | |
| dc.type | text |