High efficiency quantum photon sources, Quandela, QuanTour ft. Pascale Senellart-Mardon

In this episode

• How Pascale’s group places a quantum dot exactly between two mirrors so it sends its photons in one direction
• Why identical photons matter for quantum computing, and how her team made them 99.5% identical
• How that lab work became Quandela, the company she co-founded, and its quantum computer on the cloud
• Chains of entangled photons for error correction, and fundamental work on what heat means at the quantum level
• Her path from teenage internships at a radio astronomy station to École Polytechnique and C2N in Paris, and why she sees engineering as just as noble as fundamental science
• The surprise she is proudest of: a quantum dot that emits one photon and no photon at the same time, and her three wishes: a slower pace for science, more trust between politicians and scientists, and less gender bias

Key Takeaways

• Research director at CNRS (C2N, Paris-Saclay), Ecole Polytechnique lecturer, French Presidential Science Council and Academy of Science member, and co-founder of Quandela, she loves marrying fundamental science and industry.
• Her group spent ~20 years learning to place a quantum dot precisely inside an optical cavity so it emits bright (80%), then highly indistinguishable (99.5%) single photons, the trigger for founding Quandela in 2017 (now ~100 people).
• Quandela built a modular photonic quantum computer on the cloud (2022–23) needing only a wall-plug fridge; recent work: spin-entangled photon ’necklaces’ for error correction.
• Insists engineering is as noble as fundamental science, each enables the other.
• Was an insecure young scientist; three wishes: clone herself / more free time, slow the pace of science so people can think, better scientist–politician trust, and less gender bias.

About the guest

Pascale Senellart-Mardon is a Research Director at CNRS at the Centre for Nanoscience and Nanotechnology (C2N), Université Paris-Saclay, and an Associate Professor at École Polytechnique in France. She is the co-founder of Quandela, a member of the French Academy of Sciences, and sits on the French Presidential Council for Science.