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arXiv 1601.06154cond-mat.mes-hallcond-mat.str-elhep-th
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二维半涡旋与分数电荷

Half vortex and fractional electrical charge in two dimensions

Bitan Roy, Igor F. Herbut

摘要:

尽管有费米子加倍,当一个大质量的有序相支持一个“半涡旋”时,一个二维准相对论自旋1/2系统仍然可以导致电荷的真正分馏。当以狄拉克质量形式表示的序参量用两个$U(1)$角描述,并且每个角绕一点以一个角$π$缠绕时,这种拓扑缺陷是可能的.我们证明,这样的质量配置在一个八维狄拉克哈密顿量只表现出一个单一的束缚零模式,因此绑定的电荷$e/2$。例如,在石墨烯中,这种有序相由易平面自旋三重态凯库勒价键固体提供。我们认为,一个平面内的磁场的应用程序可以导致激子不稳定性对这样的有序相,即使是弱排斥,当在现场,最近的邻居和第二邻居组件,它是相当的强度。

英文摘要:

Despite fermion doubling, a two-dimensional quasi-relativistic spin-1/2 system can still lead to true fractionalization of electrical charge, when a massive ordered phase supports a "half-vortex". Such topological defect is possible when the order parameter in form of Dirac mass is described by two $U(1)$ angles, and each of them winds by an angle $π$ around a point. We demonstrate that such a mass configuration in an eight-dimensional Dirac Hamiltonian exhibits only a single bound zero mode, and therefore binds the charge of $e/2$. In graphene, for example, such an ordered phase is provided by the easy-plane spin-triplet Kekule valence bond solid. We argue that an application of an in-plane magnetic field can cause an excitonic instability toward such ordered phase, even for weak repulsion, when the on-site, nearest-neighbor and second neighbor components of it are of comparable strengths.

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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