Complete Coherent Control of a Quantum Dot Strongly Coupled to a Nanocavity.

Constantin Dory,Armand Rundquist,Kevin A Fischer,Kai Müller,Konstantinos G Lagoudakis,Tomas Sarmiento,Jingyuan L Zhang,Jelena Vučković,Yousif Kelaita

doi:10.1038/srep25172

Abstract

Strongly coupled quantum dot-cavity systems provide a non-linear configuration of hybridized light-matter states with promising quantum-optical applications. Here, we investigate the coherent interaction between strong laser pulses and quantum dot-cavity polaritons. Resonant excitation of polaritonic states and their interaction with phonons allow us to observe coherent Rabi oscillations and Ramsey fringes. Furthermore, we demonstrate complete coherent control of a quantum dot-photonic crystal cavity based quantum-bit. By controlling the excitation power and phase in a two-pulse excitation scheme we achieve access to the full Bloch sphere. Quantum-optical simulations are in good agreement with our experiments and provide insight into the decoherence mechanisms.

Highlights

The rapid technological development of classical computing will soon reach fundamental limitations resulting from device miniaturization
A system composed of a single quantum dots (QDs) strongly coupled to an L3 photonic crystal cavity[21] is the focus of our investigations
In order to get a better understanding of the damping mechanisms, we developed a quantum optical model based on a phenomenological two-level system using the Quantum Toolbox in PYTHON (QuTiP)[37]

Summary

Introduction

The rapid technological development of classical computing will soon reach fundamental limitations resulting from device miniaturization. The operational-range and the physical properties of QDs are limited, in particular low emission rates impede their application as non-classical light sources in photonic devices. Strongly coupled QD-cavity systems offer highly efficient out-coupling allowing for on-chip integration[9,10,11,12]. They have proven to be extremely versatile, since the hybridization of electromagnetic waves and matter forms polaritons, yielding rich physical characteristics. It is possible to control the spontaneous emission of a QD in an optical cavity[13], while the interaction of excitons and phonons[14] allows for applications such as indistinguishable photon generation[15]. In experiments supported by simulations, we map out the excitation power and phase-dependent emission from a polaritonic system and we demonstrate full access of the Bloch sphere

Methods

Results

Conclusion