Discriminatory optical force for chiral molecules

Cameron, R.P., Barnett, S.M. and Yao, A.M. (2014) Discriminatory optical force for chiral molecules. New Journal of Physics, 16(013020), (doi: 10.1088/1367-2630/16/1/013020)

Abstract

We suggest that the force F exerted upon a chiral molecule by light assumes the form under appropriate circumstances, where a and b pertain to the molecule whilst w and h are the local densities of electric energy and helicity in the optical field; the gradients of these quantities thus governing the molecule's centre-of-mass motion. Whereas a is identical for the mirror-image forms or enantiomers of the molecule, b has opposite signs; the associated contribution to F therefore pointing in opposite directions. A simple optical field is presented for which vanishes but does not, so that F is absolutely discriminatory. We then present two potential applications: a Stern–Gerlach-type deflector capable of spatially separating the enantiomers of a chiral molecule and a diffraction grating to which chiral molecules alone are sensitive; the resulting diffraction patterns thus encoding information about their chiral geometry.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Barnett, Professor Stephen and Yao, Dr Alison
• Authors: Cameron, R.P., Barnett, S.M., and Yao, A.M.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: New Journal of Physics
• Publisher: Institute of Physics Publishing Ltd.
• ISSN: 1367-2630
• ISSN (Online): 1367-2630
• Copyright Holders: Copyright © 2014 IOP Publishing Ltd.
• First Published: First published in New Journal of Physics 16:013020
• Publisher Policy: Reproduced under a Creative Commons License