Giant Polarization Drag in a Gas of Molecular Superrotors

Experiments on light dragging in a moving medium laid the cornerstones of modern physics more than a century ago, and they still are in the focus of current research. When linearly polarized light is transmitted through a rotating dielectric, the polarization plane is slightly rotated -- a phenomenon first studied by Fermi in 1923. For typical non-resonant dielectric materials, the measured polarization drag angle does not surpass several microradians. Here we show that this effect may be dramatically enhanced if the light is sent to a gas of fast unidirectionally spinning molecular superrotors. Several femtosecond-laser labs have already succeeded in optically creating such a medium. We show that the specific rotation power of the superrotor medium exceeds the values previously observed in mechanically rotated bulk optical specimens by many orders of magnitude. This nonreciprocal opto-mechanical phenomenon may open new avenues for ultra-fast control of the polarization state of light.