Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
Maryland Nanocenter, University of Maryland, College Park, Maryland 20742, USA.
Phys Rev Lett. 2019 Aug 2;123(5):053903. doi: 10.1103/PhysRevLett.123.053903.
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.
光子拖拽效应，即吸收或重定向光时动量守恒引起的介质中的整流电流，是辐射压力基本机制的独特探针。我们在金中重新研究了这一效应，金是典型的德拜金属。我们发现，在环境空气中，p 偏振光照明的信号在符号和幅度上都受到吸附分子的影响，这使得以前的测量结果需要重新解释。此外，我们表明，光子拖拽效应的固有符号与普遍存在的自由电子直接动量传递直观模型相反。
