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arXiv 2104.02892cond-mat.str-el
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[111]磁场中Kitaev模型的理论

Theory of the Kitaev model in a [111] magnetic field

Shang-Shun Zhang, Gábor B. Halász, Cristian D. Batista

摘要:

最近的数值研究表明,反铁磁Kitaev蜂窝晶格模型经历了一个磁场诱导的量子相变到一个新的自旋液相。这种中间场相先前已被表征为无隙自旋液体。通过实施一个最近发展的变分方法的基础上的零场模型的精确分数激发,我们证明了场诱导的自旋液体是带隙的,属于Kitaev的16倍的方式。具体地,具有陈数$C=\pm 1$的低场非阿贝尔液体转变为具有$C=\pm 4$的阿贝尔液体。临界场和关键物理量的场相关行为与已发表的数值结果有很好的定量一致性。此外,我们推导了场诱导临界点的有效场论,它很容易解释中间场自旋液体表面上的无隙性质。

英文摘要:

Recent numerical studies indicate that the antiferromagnetic Kitaev honeycomb lattice model undergoes a magnetic-field-induced quantum phase transition into a new spin-liquid phase. This intermediate-field phase has been previously characterized as a gapless spin liquid. By implementing a recently developed variational approach based on the exact fractionalized excitations of the zero-field model, we demonstrate that the field-induced spin liquid is gapped and belongs to Kitaev's 16-fold way. Specifically, the low-field non-Abelian liquid with Chern number $C=\pm 1$ transitions into an Abelian liquid with $C=\pm 4$. The critical field and the field-dependent behaviors of key physical quantities are in good quantitative agreement with published numerical results. Furthermore, we derive an effective field theory for the field-induced critical point which readily explains the ostensibly gapless nature of the intermediate-field spin liquid.

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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