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Updated: Jul 5, 2025

Resonance Fluorescence of an InGaAs Quantum Dot in a Planar Cavity Using Orthogonal Excitation and Detection
Published on: October 13, 2017
Giant optical polarisation rotations induced by a single quantum dot spin.
E Mehdi1,2, M Gundín1, C Millet1
1Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France.
Researchers demonstrated giant polarization rotations of photons using a single electron spin in a quantum dot. This breakthrough advances deterministic control for quantum information processing and optical quantum computing.
Area of Science:
- Quantum Information Science
- Solid-State Physics
- Optics
Background:
- Scalable quantum computing and communication require efficient spin-photon interfaces.
- Solid-state emitters in optical cavities are key for developing quantum receiving nodes.
- Deterministic control of spin-dependent photon states remains a significant challenge.
Purpose of the Study:
- To demonstrate giant polarization rotations of photons induced by a single electron spin.
- To develop a method for stable and controllable spin-photon interfaces.
- To enable conditional operations on photons for quantum information applications.
Main Methods:
- Utilizing an electrically-contacted pillar cavity embedding a single Indium Gallium Arsenide (InGaAs) quantum dot.
- Employing a complete tomography approach to analyze output photon polarization.
- Investigating spin and charge fluctuations to extrapolate conditioned polarization states.
Main Results:
- Achieved giant polarization rotations on reflected photons by a single electron spin.
- Experimentally approached conditional rotations of π/2, π, and 3π/2 with high extrapolated fidelities (up to 97%).
- Demonstrated control over photon polarization in both longitude and latitude on the Poincaré sphere.
Conclusions:
- Enhanced light-matter coupling, reduced cavity birefringence, and spectral fluctuations enable precise polarization control.
- The demonstrated spin-photon interface offers a pathway to adaptable quantum information protocols.
- This work is crucial for advancing optical quantum computing and communications by enabling tailored spin-photon interactions.
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