Winding Topology of Multifold Exceptional Points

Autor:	Yoshida, Tsuneya, König, J. Lukas K., Rødland, Lukas, Bergholtz, Emil J., Stålhammar, Marcus
Rok vydání:	2024
Předmět:	Condensed Matter - Mesoscale and Nanoscale Physics Condensed Matter - Other Condensed Matter Condensed Matter - Quantum Gases Condensed Matter - Statistical Mechanics Quantum Physics
Druh dokumentu:	Working Paper
Popis:	Despite their ubiquity, systematic characterization of multifold exceptional points, $n$-fold exceptional points (EP$n$s), remains a significant unsolved problem. In this article, we characterize Abelian topology of eigenvalues for generic EP$n$s and symmetry-protected EP$n$s for arbitrary $n$. The former and the latter emerge in a $(2n-2)$- and $(n-1)$-dimensional parameter space, respectively. By introducing resultant winding numbers, we elucidate that these EP$n$s are stable due to topology of a map from a base space (momentum or parameter space) to a sphere defined by these resultants. Our framework implies fundamental doubling theorems of both generic EP$n$s and symmetry-protected EP$n$s in $n$-band models. Comment: 10pages, 2 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2409.09153 Zobrazit plný text záznamu View this record from Arxiv