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

TL;DR

This paper demonstrates complete coherent control of a quantum dot coupled to a nanocavity, enabling manipulation of quantum states for quantum-optical applications through resonant excitation and phase control.

Contribution

We achieve full Bloch sphere control of a quantum dot-photonic crystal cavity system, advancing quantum manipulation techniques in solid-state platforms.

Findings

Observation of coherent Rabi oscillations and Ramsey fringes

Successful two-pulse phase control of quantum states

Quantum-optical simulations match experimental results

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.