Dynamical generation of superconducting order of different symmetries in hexagonal lattices
Dynamical generation of superconducting order of different symmetries in hexagonal lattices
复制标题
六方晶格中不同对称性超导序的动态生成
DOI：
10.1103/physrevb.96.195110
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发表时间：
2017
影响因子：
3.7
通讯作者：
A. Mitra
中科院分区：
文献类型：
--
作者：
Hossein Dehghani;A. Mitra
研究了六方晶格中相互作用淬灭后超导有序的生长。探索了时间反转 (TR) 保存石墨烯的情况以及 TR 破坏 Haldane 模型的情况。研究了单线态超导阶，其中 $s$、$d+id$ 和 $d-id$ 波阶是六方晶格的不可约表示。对于小淬火，$d$波阶参数增长最快，当系统处于热平衡时，也是预期的结果。对于 TR 对称性保持情况，两个 $d$ 波级的增长率相同，而 TR 破缺情况则更喜欢手性 d 波级中的一个而不是另一个，从而导致 TR 破缺拓扑超导体。随着相互作用淬灭变得更大，会发现平滑的交叉，最终 $s$ 波的增长率变得最大。因此，对于大相互作用猝灭，对于 TR 保留和 TR 破坏系统，$s$ 波优于 $d$ 波。这一结果可以用高能准粒子来解释，该高能准粒子负责随着相互作用淬灭幅度的增加而产生的动力学。
The growth of superconducting order after an interaction quench in a hexagonal lattice is studied. The cases of both time-reversal (TR) preserving graphene, as well as the TR broken Haldane model are explored. Singlet superconducting order is studied where the $s$, $d+id$, and $d-id$ wave orders are the irreducible representations of the hexagonal lattice. For small quenches, the $d$-wave order parameter grows the fastest, a result also expected when the system is in thermal equilibrium. For the TR symmetry preserving case, the growth rate of the two $d$-wave orders is identical, while the TR-broken case prefers one of the chiral d-wave orders over the other, leading to a TR broken topological superconductor. As the interaction quench becomes larger, a smooth crossover is found where eventually the growth rate of the $s$-wave becomes the largest. Thus for large interaction quenches, the $s$-wave is preferred over the $d$-wave for both TR preserving and TR broken systems. This result is explained in terms of the high energy quasi-particles responsible for the dynamics as the interaction quench amplitude grows.