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arXiv 1005.0932cond-mat.str-el
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形变蜂窝晶格上自旋1/2海森堡反铁磁体的量子相变、O(3)普适类和Phase Diagram:张量重整化群研究

Quantum Phase Transition, O(3) Universality Class and Phase Diagram of Spin-1/2 Heisenberg Antiferromagnet on Distorted Honeycomb Lattice: A Tensor Renormalization Group Study

Wei Li, Shou-Shu Gong, Yang Zhao, Gang Su

摘要:

用张量重整化群方法研究了扭曲蜂窝晶格上自旋为1/2的海森堡反铁磁体。结果表明,在耦合比α c = 0.54的临界点,体系发生了从带隙的量子二聚体相到共线Neel相的二级量子相变,得到了量子临界指数ν= 0.69(2),γ= 1.363(8).量子临界性属于O(3)普适类。提出了场耦合比平面中的基态相图,其中确定了诸如二聚体、半经典Neel和极化相等相。本文还讨论了本自旋系统与DHC晶格上玻色子哈伯德模型之间的联系。

英文摘要:

The spin-1/2 Heisenberg antiferromagnet on the distorted honeycomb (DHC) lattice is studied by means of the tensor renormalization group method. It is unveiled that the system has a quantum phase transition of second-order between the gapped quantum dimer phase and a collinear Neel phase at the critical point of coupling ratio α_{c} = 0.54, where the quantum critical exponents ν= 0.69(2) and γ= 1.363(8) are obtained. The quantum criticality is found to fall into the O(3) universality class. A ground-state phase diagram in the field-coupling ratio plane is proposed, where the phases such as the dimer, semi-classical Neel, and polarized phases are identified. A link between the present spin system to the boson Hubbard model on the DHC lattice is also discussed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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