Superconducting quantum criticality in three-dimensional Luttinger semimetals
Superconducting quantum criticality in three-dimensional Luttinger semimetals
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DOI：
10.1103/physrevb.93.205138
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发表时间：
2016-02
影响因子：
3.7
通讯作者：
I. Boettcher;I. Herbut
中科院分区：
文献类型：
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作者：
I. Boettcher;I. Herbut
我们研究了一个接近二次带接触点的三维费米子的简单模型，该模型由著名的Luttinger单粒子哈密顿量和粒子之间吸引人的接触相互作用建立起来。这样的系统在半金属和S波超导相之间显示了一个新的量子临界点，在这个临界点上，低能的“吕廷格费米子”与序参数涨落难解难分地耦合在一起。量子临界点在四个空间维度附近是微扰可达的，它具有动力学指数为1<；z<；2的非平凡标度，以及浮现的旋转和粒子-空穴对称性。讨论了临界性的一些特征，如对标度的振荡修正和对称性的增强。
We study a simple model of three-dimensional fermions close to a quadratic band touching point, built from the celebrated Luttinger single-particle Hamiltonian and an attractive contact interaction between the particles. Such a system displays a novel quantum critical point between the semimetallic and an s-wave superconducting phase at which the low-energy "Luttinger fermions" are inextricably coupled to the order parameter fluctuations. The quantum critical point is perturbatively accessible near four spatial dimensions, where it features nontrivial scaling with dynamical exponent 1<z<2 and emergent rotational and particle-hole symmetries. Some features of the criticality, such as oscillatory corrections to scaling and its enhanced symmetry, are discussed.