JOURNAL OF STATISTICAL PHYSICS 76(3-4) 745-803 1994年8月
We consider a quantum many-body system on a lattice which exhibits a spontaneous symmetry breaking in its infinite-volume ground states, but in which the corresponding order operator does not commute with the Hamiltonian. Typical examples are the ...
COMMUNICATIONS IN MATHEMATICAL PHYSICS 158(1) 191-214 1993年11月
We extend Griffith's theorem on symmetry breaking in quantum spin systems to the situation where the order operator and the Hamiltonian do not commute with each other. The theorem establishes that the existence of a long range order in a symmetric...
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 62(10) 3402-3412 1993年10月
We question the validity of the finite-size-correction method based on conformal field theories. It is shown that the method leads to incorrect critical exponents on some of the correlation functions for a one-dimensional free fermion model. The m...
JOURNAL OF STATISTICAL PHYSICS 71(1-2) 269-297 1993年4月
We propose a new Monte Carlo method for calculating eigenvalues of transfer matrices leading to free energies and to correlation lengths of classical and quantum many-body systems. Generally, this method can be applied to the calculation of the ma...
We prove the bound m(s)(beta) greater-than-or-equal-to square-root 3 sigma(beta) between the spontaneous staggered magnetization m(s)(beta) and the long range order parameter sigma(beta) in the quantum Heisenberg antiferromagnets. The same bound h...