8 papers
Hole Dynamics in the Orthogonal-Dimer Spin System
Y. Saito, A. Koga, N. Kawakami
The dynamics of a doped hole in the orthogonal-dimer spin system is investigated systematically in one, two and three dimensions. By combining the bond-operator method with the sel…
Dynamically Induced Multi-Channel Kondo Effect
T. Fujii, N. Kawakami
We study how the multi-channel Kondo effect is dynamically induced to affect the photoemission and the inverse photoemission spectrum when an electron is emitted from (or added to)…
Magnetic Double Structure for S=1, 1/2 Mixed-Spin Systems
Y. Takushima, A. Koga, N. Kawakami
We investigate the zero-temperature and the finite-temperature properties of the two-dimensional antiferromagnetic quantum spin system composed of the s=1/2 and s=1 spins. The spin…
Critical Properties in Dynamical Charge Correlation Function for the One-Dimensional Mott Insulator
T. Fujii, N. Kawakami
Critical properties in the dynamical charge correlation function for the one-dimensional Mott insulator are studied. By properly taking into account {\it the final-state interactio…
Critical Properties in Photoemmision Spectra for One Dimensional Orbitally Degenerate Mott Insulator
T. Fujii, Y. Tsukamoto, N. Kawakami
Critical properties in photoemission spectra for the one-dimensional Mott insulator with orbital degeneracy are studied by exploiting the integrable {\it t-J} model, which is a sup…
Two-Dimensional Quantum Spin Systems with Ladder and Plaquette Structure
A. Koga, S. Kumada, N. Kawakami
We investigate low-energy properties of two-dimensional quantum spin systems with the ladder and plaquette structures, which are described by a generalized antiferromagnetic Heisen…