Stress enhances quantum dot performance, QuanTour ft. Rinaldo Trotta

Stress enhances quantum dot performance, QuanTour ft. Rinaldo Trotta

In Other Words

Discovering that because every quantum dot is slightly asymmetric, you need two (later three) independent strains, one to rotate, one to make it symmetric, applied locally, so any quantum dot can be tuned to emit polarisation-entangled photon pairs.

Key Takeaways

• Professor at Sapienza University of Rome; deliberately stresses epitaxial quantum dots with strain, electric and magnetic fields to force them to emit entangled photons for long-distance secure quantum communication.
• Entanglement explained with dice: two entangled particles give individually random but perfectly correlated results, and no third party can take a share.
• Long-distance links can’t use amplifiers (no-cloning); entanglement swapping between repeater nodes (and satellites, demonstrated in China) extends range beyond ~100 km.
• Long history with Armando Rastelli (met in Dresden, followed him to Linz); built two labs from empty rooms, stressful but fun.
• Three wishes: more time for research and teaching (less bureaucracy) and permanent positions for young researchers so brilliant people aren’t lost from academia.