Hidden charge order of interacting Dirac fermions on the honeycomb lattice
Hidden charge order of interacting Dirac fermions on the honeycomb lattice
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DOI：
10.1103/physrevb.98.161120
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发表时间：
2018-06
影响因子：
3.7
通讯作者：
Elliot Christou;B. Uchoa;F. Kruger
中科院分区：
文献类型：
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作者：
Elliot Christou;B. Uchoa;F. Kruger
我们考虑蜂窝晶格上的扩展半填充哈伯德模型，用于第二最近邻相互作用。使用函数积分方法，我们发现集体涨落抑制拓扑状态，反而有利于电荷排序，这与之前的数值研究一致。然而，我们表明临界点不是假定的半金属莫特绝缘体。由于相互作用的受挫性质，基态由具有半狄拉克激发的新型隐藏金属电荷顺序描述。我们推测这种转变不属于 Gross-Neveu 普遍性类别。
We consider the extended half-filled Hubbard model on the honeycomb lattice for second nearest-neighbor interactions. Using a functional integral approach, we find that collective fluctuations suppress topological states and instead favor charge ordering, in agreement with previous numerical studies. However, we show that the critical point is not of the putative semimetal-Mott insulator variety. Due to the frustrated nature of the interactions, the ground state is described by a novel hidden metallic charge order with semi-Dirac excitations. We conjecture that this transition is not in the Gross-Neveu universality class.