https://arxiv.org/pdf/1812.01673.pdf https://arxiv.org/pdf/1812.01673.pdf > The photon-drag effect, the rectified current in a medium induced by conservation o

https://arxiv.org/pdf/1812.01673.pdf https://arxiv.org/pdf/1812.01673.pdf > The photon-drag effect, the rectified current in a medium induced by conservation of momentum of absorbed or redirected light, is a unique probe of the detailed mechanisms underlying radiation pressure. We revisit this effect in gold, a canonical Drude metal. We discover that the signal for p- polarized illumination in ambient air is affected in both sign and magnitude by adsorbed molecules, opening previous measurements for reinterpretation. Further, we show that the intrinsic sign of the photon-drag effect is contrary to the prevailing intuitive model of direct momentum transfer to free electrons.