Quantum friction through monolayers

Quantum friction is a friction force caused by electromagnetic fluctuations as an atom moves relative to macroscopic bodies. This effect is only predicted theoretically and requires high velocity and close proximity to give a significant signal. To date, experiments have not been able to measure this effect. Recent experiments with ultrafast atoms have sent neutral atoms through the crystal structure of monolayer graphene [. We present a theoretical framework describing quantum friction as atoms pass through monolayers and calculate the force on helium passing through graphene. Once the atom passes the monolayer, we find that the velocity-dependent force no longer opposes the direction of motion due to strong interactions caused by having been closer to the monolayer in the past. For the experimental parameters, we find a kinetic energy loss caused by quantum friction on the order of ten to hundred µ eV . We find that quantum friction cannot be measured with this setup with current techniques.