The world around us is made of two fundamentally different kinds of particles: fermions and bosons. Fermions are solitary by nature — if they were cars on a busy road, each one would be forced to respect the space in front and avoid others. Bosons, on the other hand, are far more sociable. They like to group together. In the world of bosonic quantum vehicles, traffic jams simply don’t exist — these cars actually want to overlap.
Yet, according to new research published in Physical Review Letters, there is a hidden connection between these two kinds of particles — one that becomes visible when studying the fluctuations of their flow around its average. Remarkably, these fluctuations follow the same universal law for both types of particles. This surprising universality, demonstrated through a rigorous mathematical approach, provides a powerful new tool for understanding quantum transport. Even more surprisingly, the same law also governs seemingly unrelated natural phenomena, such as the growth of crystal surfaces or the spread of wildfires.
This research is the result of a collaboration between Professor Andrea Gambassi of the Statistical Physics group at SISSA and colleagues and doctoral students from the Technical Universities of Vienna and Munich.