Journal of the Physical Society of Japan
Bethe-Ansatz Analysis of the Extended AB Period in the One-Dimensional Hubbard Model
Koichi Kusakabe
Abstract
The extended spectral flow at the normal-superconducting transition is investigated for the one-dimensional Hubbard model. Recombination of spectral flow lines at U =±0, which causes halving of the extended Aharonov-Bohm period for U <0 found in a recent paper [K. Kusakabe and H. Aoki: J. Phys. Soc. Jpn. 65 (1996) 2772], is exactly analyzed using the Bethe ansatz solution. Adiabatic motion of charge rapidities which are real for U >0 (normal Luttinger liquid) or complex for U <0 (superconducting Luther-Emery liquid) dominates sudden response of the spectral flow at the transition point. The extended period is obtained not only against the charge flux but also against the spin flux for both U >0 and U <0.