General Quantum Backflow in Realistic Wave Packets

Author(s): Tomasz Paterek and Arseni Goussev Quantum backflow is a counterintuitive phenomenon in which the probability density of a quantum particle propagates opposite to its momentum. Experimental observation of backflow has remained elusive due to two main challenges: (i) the effect is intrinsically small, with less than 4% of the probabil… [Phys. Rev. Lett. 136, 090202] Published Mon Mar 02, 2026