Quantum backflow in biased tight-binding systems
Phys. Rev. A 113, 032218 – Published 23 March, 2026
DOI: https://doi.org/10.1103/v49b-zz68
Abstract
We study the phenomenon of quantum backflow in tight-binding systems with complex couplings, considering different boundary conditions and lattice sizes. Backflow is an intrinsically nonclassical effect where the density flux associated with a particle described by the superposition of wave functions with, say, positive momentum, acquires negative values. We calculate the superposition of positive-momentum states that gives rise to the strongest backflow in the system. We also evaluate the bounds on the total amount of probability that flows in the opposite direction of the particle's momentum.
