Physicists trapped a cloud of lithium atoms between mirrors. Light bounces inside, like in an echo chamber, forcing the atoms to emit synchronously — resulting in superradiance, akin to a choir where voices merge into a single thunder.
The secret is density. Atoms too sparse can't hear each other; too crowded — fermions start clashing: the Pauli principle forbids them from occupying the same state, like two singers trying to hit the same note. The superradiance threshold behaves cunningly: first it drops, then rises. The ideal is reached when the distance between atoms matches the light wavelength — then neighbors' help turns into jostling. Another surprise: atoms with different 'spin' separate into waves, alternating in stripes. By controlling this pattern, we can create quantum devices with unprecedented sensitivity. Moreover, superradiance gathers light into a single chord, millions of times faster than individual glow — discordant voices become a thunderous strike. The glow was monitored using spectroscopy methods.
The term 'superradiance' first appeared in astrophysics to describe black hole radiation, and now it's studied in labs with clouds of atoms.