You can use 'quantum noise' to force atoms to spit out light that's technically supposed to be impossible.
March 26, 2026
Original Paper
Fluctuation-induced symmetry breaking in high harmonic generation for bicircular quantum light
arXiv · 2603.24377
The Takeaway
Symmetries in physics act like strict rules that decide which atomic transitions are allowed and which are impossible. Researchers found that by using specialized 'squeezed' quantum light, they can use vacuum fluctuations to break these rules and generate light frequencies that should not exist under classical conditions.
From the abstract
Symmetries are ubiquitous in physics and play a pivotal role in light-matter interactions, where they determine the selection rules governing allowed atomic transitions and define the associated conserved quantities. For the up-conversion process of high harmonic generation, the symmetries of the driving field determine the allowed frequencies and the polarization properties of the resulting harmonics. As a consequence, it is possible to establish classical selection rules when the process is dr