New nuclear-spin-induced Cotton-Mouton effect in fluids at high DC magnetic field.

Based on Buckingham and Pople's theory of magnetic double refraction, a theoretical expression is derived for a new Cotton-Mouton effect φ(C-M)((IB)) in liquid induced by the crossed effect between the high dc magnetic field B(0) and the nuclear magnetic moment m(z)((l)). It contains temperature-independent and -dependent parts. The latter is proportional to the product between anisotropy of polarizability and the nuclear magnetic shielding tensor. For this new effect φ(C-M)((IB)), its order in magnitude for a molecule with large polarizability anisotropy is estimated to be comparable to the nuclear-spin-induced optical Faraday rotation (NSOFR). In the multipass approach, φ(C-M)((IB)) can be eliminated by time-reversal symmetry arguments, but NSOFR is enhanced.