Chocolate Chips & Relaxed Quantum Dots ft. Armando Rastelli

In Other Words

Figuring out during his postdoc how to make quantum dots without strain, overturning the assumption that stress is the driving force for dot formation; he grew the sample overnight and saw the proof of a new kind of ‘golden dot’ at 6 a.m., and 20 years later strain-free dots are taking over the field.

Key Takeaways

Professor at Johannes Kepler University Linz making epitaxial quantum dots (~50 nm wide, ~7 nm tall), ‘chocolate chips in a 5-km muffin’, for optoelectronic and quantum-light applications.
Colloidal quantum dots (spherical, 2023 Nobel) go into bright TV screens; epitaxial dots are better for lasers and single/entangled-photon sources like the QuanTour source.
The QuanTour ‘bullseye’ cavity is a specialised high-efficiency lens with a back mirror that funnels ~90% of emitted single photons into a fibre.
During his PhD he peeled graphite with Scotch tape to calibrate an STM and threw the flakes away, ‘I missed the Nobel Prize’.
One wish: far less bureaucracy in grants and reporting. Co-leads QuanTour and the Quantum Science Austria (QuantA) fundamental-science cluster.