Experimental evidence of the B² and B³ dependent circular birefringence of chiral molecules in high magnetic fields

Abstract

The rotation of the plane of polarization of light passing through chiral media in the Faraday geometry of a magnetic field B and light propagation vector k have been measured in high magnetic fields of induction up to 30 T and a laser beam wavelength λ = 488 nm. The optically active enantiomers of neat α-methylbenzylamine and solutions in water of tartaric, malic and lactic acids, leucine and threonine exhibit dependence of the induced rotation of the light polarization plane on B ² and B ³. The effect is reported of the magnetic field B ² induced circular birefringence of laevorotatory and dextrorotatory enantiomers. Also differences are found in the effective rotation of the plane of polarization in the parallel (α^↑↑) and antiparallel (α^↑↓) configurations of B and k acting on a chiral medium. The first quantitative determination is made of the nonlinear (B ³) Faraday effect in chiral media. The linear in B circular birefringence makes the largest contribution to the B ² and B ³ dependent rotation.