SCHWINGER-BOSON MEAN-FIELD THEORY FOR S = 1 OPEN SPIN CHAINS

[摘要] The properties of S = 1 open spin chains is studied using Schwinger-boson mean-field theory. It is found that localized S = 1/2 states exist at the ends of chains and that the ground states of chains with even and odd number of sites are fundamentally different. Properties of the localized end states are discussed.

[关键词] BOND GROUND-STATES;ANTIFERROMAGNET