Fermion-induced quantum criticality with two length scales in Dirac systems
Fermion-induced quantum criticality with two length scales in Dirac systems
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DOI：
10.1103/physrevb.97.125137
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发表时间：
2018-02
影响因子：
3.7
通讯作者：
Emilio Torres;L. Claßen;I. Herbut;M. Scherer
中科院分区：
文献类型：
--
作者：
Emilio Torres;L. Claßen;I. Herbut;M. Scherer
二维Dirac半金属中到$\mathbb{Z}_3$-有序Kekul\'e价键固体的量子相变由费米子诱导的量子临界点控制，这使得pupe不连续相变连续.我们研究了由此产生的普遍的临界行为的功能RG的方法，这使得访问的标度行为的相变的破缺侧，一般尺寸和数量的狄拉克费米子。特别地，我们研究了空间-时间维度$2<d<4$的费米子诱导量子临界点的出现。我们确定了从狄拉克半金属的积分RG流的破缺制度，并分析了潜在的不动点结构。我们表明，费米子诱导的临界导致一个标度形式与两个不同的长度尺度，由于离散的$\mathbb{Z}_3$对称性的破坏。除了源于接近一阶跃迁的源之外，这提供了缩放校正的另一个源。
The quantum phase transition to a $\mathbb{Z}_3$-ordered Kekul\'e valence bond solid in two-dimensional Dirac semimetals is governed by a fermion-induced quantum critical point, which renders the putatively discontinuous transition continuous. We study the resulting universal critical behavior in terms of a functional RG approach, which gives access to the scaling behavior on the symmetry-broken side of the phase transition, for general dimension and number of Dirac fermions. In particular, we investigate the emergence of the fermion-induced quantum critical point for space-time dimensions $2<d<4$. We determine the integrated RG flow from the Dirac semi-metal to the symmetry-broken regime and analyze the underlying fixed point structure. We show that the fermion-induced criticality leads to a scaling form with two divergent length scales, due to the breaking of the discrete $\mathbb{Z}_3$ symmetry. This provides another source of scaling corrections, besides the one stemming from being in the proximity to the first order transition.