Quantum phase transition between cluster and antiferromagnetic states
Quantum phase transition between cluster and antiferromagnetic states
复制标题
团簇态和反铁磁态之间的量子相变
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
V. Vedral
中科院分区：
文献类型：
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作者：
W. Son;L. Amico;R. Fazio;A. Hamma;S. Pascazio;V. Vedral
我们研究了一个描述三自旋1/2簇状相互作用与类伊辛交换竞争的哈密顿系统。我们证明了簇相中的基态具有对称保护的拓扑秩序。连续的量子相变是星团和伊辛项之间竞争的结果。在临界点处，哈密顿函数是自对偶的。几何纠缠也被用来研究量子相变。我们在一维上的发现证实了对系统二维推广的分析，表明在平均场水平上，存在反铁磁和价键固体基态之间的直接转变。
We study a Hamiltonian system describing a three–spin-1/2 cluster-like interaction competing with an Ising-like exchange. We show that the ground state in the cluster phase possesses symmetry protected topological order. A continuous quantum phase transition occurs as result of the competition between the cluster and Ising terms. At the critical point the Hamiltonian is self-dual. The geometric entanglement is also studied and used to investigate the quantum phase transition. Our findings in one dimension corroborate the analysis of the two-dimensional generalization of the system, indicating, at a mean-field level, the presence of a direct transition between an antiferromagnetic and a valence bond solid ground state.