Fast Electrical Control of a Quantum Dot Strongly Coupled to a Nano-resonator

TL;DR

This paper demonstrates rapid electrical control of a quantum dot strongly coupled to a nano-resonator, achieving fast Stark tuning and high-speed switching for potential quantum information applications.

Contribution

It introduces a method for fast electrical tuning of a quantum dot-cavity system using a lateral Schottky electrode, enabling high-speed optical switching.

Findings

Stark shifts up to 0.3 meV achieved

Switching speeds up to 150 MHz demonstrated

Coupling rate and Stark shift characterized

Abstract

The resonance frequency of an InAs quantum dot strongly coupled to a GaAs photonic crystal cavity was electrically controlled via quantum confined Stark effect. Stark shifts up to 0.3meV were achieved using a lateral Schottky electrode that created a local depletion region at the location of the quantum dot. We report switching of a probe laser coherently coupled to the cavity up to speeds as high as 150MHz, limited by the RC constant of the transmission line. The coupling rate and the magnitude of the Stark shift with electric field were investigated while coherently probing the system.