Two-Nanorod PT Structure with Large Spontaneous Enhancement

Two-mode coupling is very common and basic in optics. Recently, a lot more works are focusing on the optical mode coupling with gain and loss due to its tighter link to actual world. For a couple between one gain and one loss mode, by adjusting the coupling constant, the mode in the spectrum will at first stay then move after the constant passing some critical point. This phase transition can be explained by non-Hermitian PT phase transition theory.However, only few works research the spontaneous emission adjustment based on this procedure. It has a lot of promising utilization in on chip optic systems if we can adjust spontaneous emission. We look more deeply in this mode coupling process using metallic nanorods, find the Exceptional Point, show the phase transition between PT symmetry and PT broken regime, and show the adjustment to quantum dot emission. Our work not only promote the understanding of multi-mode system, but also bring up with a new way to adjust high enhancement of spontaneous emission, tamping the foundation for future on chip nano photonics.