论文标题
强大的特殊点的起源：限制零模式
Origin of robust exceptional points: a restricted bulk zero mode
论文作者
论文摘要
最近，发现一种强大的特殊点对散装中的耦合障碍不敏感。在这里，我们表明，当此一维阵列中的耦合腔数从偶数变为奇数时，差异就会出现。强大的特殊点仅在前一种情况下存在，而后者在后者中的特殊点的位置却取决于腔阵列的大小，并且会在大块中遇到耦合障碍。我们进一步表明，这两种情况中的特殊点分别为第二和三阶。我们将强大的EP的起源阐明为限制的零模式，该模式具有相同的对耦合障碍的鲁棒性，并且具有与边界相邻的有限幅度。这一发现使我们能够可靠地识别高维系统中的稳健EP，这可以在存在Sublattice对称性的存在或从中演变而来的非热粒子孔对称性。
Recently a type of robust exceptional points was found that is insensitive to the coupling disorder in the bulk. Here we show that a disparity emerges when the number of coupled cavities in this one-dimensional array changes from even to odd. The robust exceptional point only exists in the former case, whereas the location of the exceptional point in the latter depends inversely on the size of the cavity array and is subjected to coupling disorder in the bulk. We further show that the exceptional points in these two cases are second and third order, respectively. We elucidate the origin of the robust EP as a restricted bulk zero mode, which shares the same robustness against coupling disorder and has a finite amplitude adjacent to the boundary. This finding enables us to identify robust EPs in higher dimensional systems reliably, which can exist in the presence of either sublattice symmetry or the non-Hermitian particle-hole symmetry evolved from it.
