Degeneracies in a nonintegrable pairing model

TL;DR

This paper investigates the behavior of exceptional points in a non-integrable 3-level Richardson-Gaudin model, revealing the formation of pseudo-diabolic points from fused exceptional points in an anti-hermitian limit.

Contribution

It demonstrates the emergence of pseudo-diabolic points from fused exceptional points in a non-integrable pairing model, expanding understanding of spectral degeneracies.

Findings

Identification of exceptional point evolution patterns

Demonstration of pseudo-diabolic point formation

Analysis in anti-hermitian limit

Abstract

The evolution pattern of exceptional points is studied in a non-integrable limit of the complex-extended 3-level Richardson-Gaudin model. The appearance of a pseudo-diabolic point from the fusion of two exceptional points is demonstrated in the anti-hermitian limit of the model and studied in some details.