title: Spontaneous trimerization in two-dimensional antiferromagnets.
abstract: In this paper, we propose an exotic quantum paramagnetic state in two-dimensional antiferromagnets-the spontaneous trimer state-which is the direct product state of the trimers of spins. Each trimer is a singlet state formed by three neighboring spins with SU(3) symmetry. A frustrated spin-1 Heisenberg model in the kagome lattice is investigated. By analogy to the pseudo-potential approach in the fractional quantum Hall effect (FQHE), we find that the trimer state provides a good description for the exact ground state of this model. Other interesting properties, such as the local excitations as well as magnetization plateaus have also been investigated.
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, People's Republic of China.
authors.forename: Zi
authors.initials: Z
authors.lastname: Cai
authors.forename: Shu
authors.initials: S
authors.lastname: Chen
authors.forename: Yupeng
authors.initials: Y
authors.lastname: Wang