In a dark room, an invisible lamp flashes. Its light is unlike anything familiar: it has no steady brightness, only rare but powerful bursts. This is bright squeezed vacuum — a state of light with no ordinary wave but strong quantum fluctuations. It is with such light that physicists bombarded xenon atoms.
Each burst knocks an electron out of the atom hydrogen]. The trajectories of the emitted particles weave into intricate patterns, resembling a spider's web. Ordinary laser light blurs these patterns, but squeezed vacuum makes them brighter. The reason lies in pairs of trajectories born from the same burst. They move in sync, like two dancers holding hands, and thus never lose the rhythm. Trajectories from different bursts are out of phase and are filtered out by noise.
This effect is not just a pretty trick. It shows that quantum fluctuations can serve as a filter, selecting the desired quantum trajectories. In the future, this could allow controlling chemical reactions or the motion of electrons in materials with unprecedented precision.
Squeezed vacuum is so "empty" that on average it contains zero photons, yet its bursts can be brighter than those of a powerful laser.
In the novel "The Quantum Thief" by Hannu Rajaniemi, quantum states are used to manipulate reality — squeezed vacuum could become a tool of such a world.