Quantum critical properties in the topological Ginzburg–Landau theory of self-dual Josephson junction arrays
Quantum critical properties in the topological Ginzburg–Landau theory of self-dual Josephson junction arrays
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自对偶约瑟夫森结阵列拓扑金兹堡-朗道理论中的量子临界特性
DOI：
10.1016/j.physa.2013.08.009
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发表时间：
2013
影响因子：
3.3
通讯作者：
S. Sakhi
中科院分区：
文献类型：
--
作者：
S. Sakhi
研究了广义U（N1）× U（N2）Ginzburg-Landau理论的多临界行为，该理论包含两个多分量复场，它们与两个由两个麦克斯韦项和一个混合Chern-Simons项描述的规范场不同地耦合.这个模型与超导体-绝缘体转变附近的自对偶约瑟夫森结阵列系统中的库珀对和涡旋的动力学有关。我们发展了一个固定维的重整化群流，并得到了当两个无序场都是临界时，一个环上的β函数。当N> Nc时，得到了两组红外稳定的带电不动点解：Nc = 35.6时，存在关于规范场的部分带电不动点解; Nc = 12.16时，存在关于规范场的完全带电不动点解.我们表明，微调模型中的两个能量尺度的比例具有降低临界数N c的效果，从而扩大了量子相变连续的区域。研究还发现，当存在涨落规范场时，在中性情形下稳定的解耦不动点不再存在。我们探测临界点处的电导率，并表明它具有由规范耦合的重整化群红外稳定定点值所决定的普适性质。
This paper examines the multicritical behavior of a generalized U (N 1)× U (N 2) Ginzburg–Landau theory containing two multicomponent complex fields which couple differently to two gauge fields described by two Maxwell terms and one mixed-Chern–Simons term. This model is relevant to the dynamics of Cooper pairs and vortices in a self-dual Josephson junction array system near its superconductor–insulator transition. We develop a renormalization group flow at fixed dimension and obtain the beta functions at one loop when both disorder fields are critical. Two sets of infrared-stable charged fixed points solutions are found for N> N c: partially charged solutions with respect to the gauge fields exist with N c= 35.6, and fully charged solutions exist with N c= 12.16. We show that fine tuning the ratio of the two energy scales in the model has the effect of reducing the critical number N c and thus enlarges the region where the quantum phase transition is continuous. It is also found that the decoupled fixed point which is stable in the neutral case is no longer attainable in the presence of fluctuating gauge fields. We probe the conductivity at the critical point and show that it has a universal character determined by the renormalization group infrared-stable fixed-point values of the gauge couplings.