12 papers
Spectral flow of non-hermitian Heisenberg spin chain with complex twist
T. Fukui, N. Kawakami
We investigate the spectral flow of the integrable non-hermitian Heisenberg spin chain under boundary conditions with complex twist angle. It is shown that the period of the spectr…
Alternating-Spin Ladders
T. Fukui, N. Kawakami
We investigate a two-leg spin ladder system composed of alternating-spin chains with two-different kind of spins. The fixed point properties are discussed by using spin-wave analys…
Alternating spin chains with singlet ground states
T. Fukui, N. Kawakami
We investigate low-energy properties of the alternating spin chain model composed of spin and with a singlet ground state. After examining the spin-wave spectrum in det…
Spin Chains with Periodic Array of Impurities
T. Fukui, N. Kawakami
We investigate the spin chain model composed of periodic array of two kinds of spins and , which allows us to study the spin chains with impurities as well as the altern…
Low-Energy Properties of Regularly Depleted Spin Ladders
T. Fukui, M. Sigrist, N. Kawakami
We investigate a model for the regularly depleted two-leg spin ladder systems. By using Lieb-Schultz-Mattis theorem, it is rigorously shown that this model realizes massless excita…
SU(ν) Generalization of Twisted Haldane-Shastry Model
T. Fukui, N. Kawakami
The SU() generalized Haldane-Shastry spin chain with interaction is studied with twisted boundary conditions. The exact wavefunctions of Jastrow type are obtained for ev…