Richard Kueng

In September 2024, the concert hall in Linz had more than just an orchestra on stage. Next to the musicians, a setup was generating pairs of entangled photons: a laser with a wavelength of 405 nm passed through a nonlinear crystal and split into two photons at 810 nm, which flew off to two measurement stations, Alice and Bob.

A quantum computer is a finicky instrument. Each measurement of its state is like photographing a fast-moving object: the shorter the exposure, the higher the chance of getting a blurry shot. But if you skillfully process a series of such snapshots, you can reconstruct a clear picture. That's exactly what the researchers did.