Topological protection is a promising way to deal with the decoherence issue in quantum systems. To induce topological excitations in Josephson junction arrays (JJA), we propose a scheme where only Josephson critical currents are tuned in JJA on honeycomb lattice, which is easily achieved by changing potential barriers or lengths of insulators between superconducting islands. In the present system, a hexagonal cluster with six superconducting islands forms a unit cell, and the difference between intra- and inter-hexagon Josephson critical currents yields a topologically nontrivial state accompanied by a band inversion. Topological Josephson plasmon modes appear at the interface between topological and trivial domains, carrying pseudospin dominant energy flows, which mimics the spin-momentum locking in the renowned quantum spin Hall effect.

中文翻译：

---

蜂窝格上的拓扑约瑟夫森等离子体激元模式[已邀请]

拓扑保护是解决量子系统中退相干问题的一种有前途的方法。为了在约瑟夫森结阵列（JJA）中引发拓扑激发，我们提出了一种方案，其中仅约瑟夫森临界电流在JJA上的蜂窝晶格上得到调谐，这可以通过更改势垒或改变超导岛之间的绝缘子长度来轻松实现。在本系统中，具有六个超导岛的六边形簇形成一个晶胞，并且六边形内和六边形约瑟夫森临界电流之间的差异产生拓扑上不平凡的状态，并伴有能带反转。拓扑约瑟夫森等离子体激元模式出现在拓扑域与琐碎域之间的界面上，携带伪自旋占优势的能量流，模仿了著名的量子自旋霍尔效应中的自旋动量锁。