Physicists have discovered exact laws by which quantum entanglement mixes in chaotic systems. In a model with rhythmic jolts — like a baker kneading dough — they studied the growth of entropy of entanglement, a measure of quantum disorder. Using a trick of creating mathematical replicas to average out randomness, they calculated the spectrum of a key characteristic. It turned out flat — all outcomes equally probable, like a perfectly fair game. This yielded simple formulas linking various mixing measures in the early stages.
Further calculations showed: if you split the system into three equal parts, over time entanglement becomes maximally random — like well-kneaded dough. But with unequal parts, the connection tears, each part isolating like oil from water. Most surprising: this pattern holds for almost any initial conditions. Periodic jolts, like pulses from a pulsar, drive the quantum world to equilibrium by strict mathematical rules. This discovery will help build robust quantum computers.
This model is a rare case of an exact solution in quantum chaos: a kind of perfect recipe, which is why theoretical physicists treasure it.