Level statistics for the gapped spin-1/2 XXZ Heisenberg chains

摘要

We study the level spacing distribution of the gapped spin-1/2 XXZ Heisenberg chains. The level spacing distributions are calculated for a series of chain lengths from 10 to 19 by numerical exact diagonalization. We conclude that the missed states in the Bethe ansatz solution are statistically minor in thermodynamics limit in the whole spectrum. [References: 21]