5 papers
Recent Progress of the Low-Dimensional Spin-Wave Theory
Shoji Yamamoto
A modified spin-wave theory is developed and applied to low-dimensional quantum magnets. Double-peaked specific heat for one-dimensional ferrimagnets, nuclear spin-lattice relaxati…
Local excitations in mixed-valence bimetal chains
Shoji Yamamoto
We investigate localized intragap states in mixed-valence bimetal chains in an attempt to encourage further explorations into quasi-one-dimensional halogen-bridged binuclear metal…
Quantum and thermal phase transitions in the Bechgaard salts and their analogs
Hiromitsu Hori, Shoji Yamamoto
In order to investigate quantum and thermal phase transitions in the Bechgaard salts and their sulfur analogs, we perform finite-temperature Hartree-Fock calculations in one dimens…
Ground-State Properties of the Two-Band Model for Halogen-Bridged Metal Complexes
Shoji Yamamoto
Based on a symmetry argument, we systematically reveal Hartree-Fock broken-symmetry solutions of the one-dimensional two-band extended Peierls-Hubbard model. Performing numerical i…
Quantum Fluctuations to Cause the Breakdown of the Spin-1 Haldane Phase
Shoji Yamamoto
Investigating quantum fluctuations in the ground states of S=1 quantum antiferromagnetic spin chains described by the bilinear-biquadratic Hamiltonian, we study a mechanism of the…