Open AccessOptical torque induces magnetism at the molecular level
Author(s) -
M. Tuan Trinh,
Krishnandu Makhal,
Elizabeth F. C. Dreyer,
Apoorv Shanker,
SeongJun Yoon,
Dong Ha Kim,
Stephen C. Rand
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.021295
Subject(s) - magnetization , physics , magnetism , light scattering , scattering , condensed matter physics , electric field , magnetic dipole , magnetic field , optics , atomic physics , quantum mechanics
We report experimental observations of a mechanism that potentially supports and intensifies induced magnetization at optical frequencies without the intervention of spin-orbit or spin-spin interactions. Energy-resolved spectra of scattered light, recorded at moderate intensities (10 8 W/cm 2 ) and short timescales (<150 fs) in a series of non-magnetic molecular liquids, reveal the signature of torque dynamics driven jointly by the electric and magnetic field components of light at the molecular level. While past experiments have recorded radiant magnetization from magneto-electric interactions of this type, no evidence has been provided to date of the inelastic librational features expected in cross-polarized light scattering spectra due to the Lorentz force acting in combination with optical magnetic torque. Here, torque is shown to account for unpolarized rotational components in the magnetic scattering spectrum under conditions that produce only polarized vibrational features in electric dipole scattering, in excellent agreement with quantum theoretical predictions.