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تسجيل مستخدم جديدDuality of deconfined quantum critical point in two dimensional Dirac semimetals
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In this paper we discuss the N$acute{e}$el and Kekul$acute{e}$ valence bond solids quantum criticality in graphene Dirac semimetal. Considering the quartic four-fermion interaction $g(bar{psi}_iGamma_{ij}psi_j)^2$ that contains spin,valley, and sublattice degrees of freedom in the continuum field theory, we find the microscopic symmetry is spontaneously broken when the coupling $g$ is greater than a critical value $g_c$. The symmetry breaking gaps out the fermion and leads to semimetal-insulator transition. All possible quartic fermion-bilinear interactions give rise to the uniform critical coupling, which exhibits the multicritical point for various orders and the Landau-forbidden quantum critical point. We also investigate the typical critical point between N$acute{e}$el and Kekul$acute{e}$ valence bond solid transition when the symmetry is broken. The quantum criticality is captured by the Wess-Zumino-Witten term and there exist a mutual-duality for N$acute{e}$el-Kekul$acute{e}$ VBS order. We show the emergent spinon in the N$acute{e}$el-Kekul$acute{e}$ VBS transition , from which we conclude the phase transition is a deconfined quantum critical point. Additionally, the connection between the index theorem and zero energy mode bounded by the topological defect in the Kekul$acute{e}$ VBS phase is studied to reveal the N$acute{e}$el-Kekul$acute{e}$ VBS duality.
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