Electrical-control of third-order nonlinearity via Fano interference

TL;DR

This paper demonstrates a method to electrically tune third-order nonlinearity in a nano-plasmonic system using Fano interference and Stark effect, enabling rapid and continuous control for programmable photonic quantum computing.

Contribution

It introduces a novel design combining Fano interference and Stark effect to achieve fast, continuous electrical tuning of third-order nonlinearity in nano-plasmonic systems.

Findings

Third-order nonlinearity can be tuned within a picosecond response time.

Fano interference enhancement degrades with random QO positioning.

Finite-difference time domain simulations confirm the effect.

Abstract

Programmable photonic computers necessitate the integration of electrically-tunable compact components into the photonic devices. In the state-of-the-art photonic quantum computers~(PQCs), phase-shift and displacement gates can be implemented in an electrically-programmable way. An efficient PQC, however, necessitates also the tuning of third or higher order nonlinearity for implementing continuous-variable~(CV) gates at a shorter sequence. Here, we demonstrate that such an optical component can be designed using Fano interference and Stark effect in a nonlinear nano-plasmonic system. We study the coupling of a broadband bright plasmon mode to a narrow linewidth quantum object(s), QO(s). We show that by shifting the level-spacing of the QO via Stark effect, one can continuously tune the third-order nonlinearity gate within a picosecond response time. We also present finite-difference time domain~(FDTD) simulations that take the retardation effects into account. In addition, we also show that enhancement due to Fano interference degrades if the QOs are positioned randomly as each QO introduces different phases. This reveals the importance of the spatial extent of the QO-ensemble to be employed in the experiments.