Parts | Days | Selection | Search | Updates | Downloads | Help
TT: Fachverband Tiefe Temperaturen
TT 45: Correlated Electrons: 1D Theory
TT 45.1: Talk
Thursday, March 30, 2023, 09:30–09:45, HSZ 103
On the alternating spin chain with continuous spectrum of scaling dimensions — Mouhcine Azhari and •Andreas Klümper — Universität Wuppertal
We investigate the low-lying spectrum of an integrable staggered Heisenberg spin-1/2 chain possessing in the large length (L) limit a CFT structure with logarithmic corrections (1/(logL)2). This realizes a continuous spectrum of conformal weights similar to that of for instance the SL(2,R)/U(1) black hole sigma model.
The quantum spin chain is exactly “solvable” by Bethe ansatz and other techniques from the theory of integrability. However, the analysis of the resulting Bethe Ansatz equations is challenging and manageable by numerical techniques only for relatively small sizes L. Integral equations for the distribution functions of the Bethe roots suffer from singularities of the kernel functions.
Due these phenomena and challenges the model attracted interest by several groups of authors (Ikhlef, Jacobsen, Saleur 08, 12; Frahm, Martins 12; Candu, Ikhlef 13; Frahm, Seel 14; Bazhanov, Kotousov, Koval, Lukyanov 20).
In our contribution we report on recent progress allowing us to rewrite already existing non-linear integral equations (NLIE) with a singular, i.e. long-ranged kernel in a novel form without such problems. We present results for the lowest lying excitations for system sizes L=10, 102, 103, ...., 109, ....