In an orchestra, one musician plays so quietly that their sound is almost inaudible in the overall chorus. In the quantum world, such 'quiet' states are called dark: their energy barely escapes, like light in a darkened room. But if there are many musicians, their mutual influence can unexpectedly awaken even the most silent one.

In the new work, physicists considered a chain of spins (quantum 'tops') with a special type of dissipation acting on neighboring sites. In such a system, there exists a single-particle dark state with zero momentum: it, like a conductor, sets the rhythm but remains in the shadows. However, with a large number of particles, this state begins to slowly fade: its decay goes as [formula:decay]1/ln(t)[/formula], where t is time. It's like watching a candle flame not go out at once but smolder for a long time, obeying a tricky law.

The most surprising thing is that the system's behavior turned out to be universal. The distribution of particles over velocities (momenta) is described by a single form depending on [formula:scaling]k√t[/formula], and the total particle density falls as [formula:density]1/(√t * ln(t))[/formula]. This resembles the pattern left on sand after the tide: no matter what the tide was like, the lines remain similar. The results were confirmed by numerical simulation, and even with weak particle interactions the picture does not change — nature seems to insist on this scenario.