Chiral discrimination in optical binding

Abstract

The laser-induced intermolecular force that exists between two or more particles in the presence of an electromagnetic field is commonly termed 'optical binding'. Distinct from the single-particle forces that are at play in optical trapping at the molecular level, the phenomenon of optical binding is a manifestation of the coupling between optically induced dipole moments in neutral particles. In other, more widely known areas of optics, there are many examples of chiral discrimination -signifying the different response a chiral material has to the handedness of an optical input. In the present analysis, extending previous work on chiral discrimination in optical binding, a new mechanism is identified using a quantum electrodynamical approach. It is shown that the optical binding force between a pair of chiral molecules can be significantly discriminatory in nature, depending upon both the handedness of the interacting particles and the polarization of the incident light, and it is typically several orders of magnitude larger than previously reported.

Identifying diamagnetic interactions in scattering and nonlinear optics

“…The latter, however, assumes a traceless form as a result of its engagement with the derivative of the electric field, whose 1 ¸ . M 2 (r) 2 2…”

“…The premultiplier can be rewritten more succinctly by taking into account the degree of second-order coherence g (2) [21], where g (2) = (n(n − 1))/(n) 2 , and then making use of the fact that the beam intensity may be given as the mean irradiance I¯ = (n)ckω/V . The rate equation (31) finally becomes expressible as…”

“…In consequence, higher-order couplings expressed in multipolar form, such as the light-matter interactions mediated by a magnetic dipole, can usually be disregarded. However, these higher-order terms are important for certain systems, such as chiral discrimination in molecules of low symmetry [1,2], light-harvesting complexes [3], nanomaterials [4][5][6], metamaterials [7,8] and numerous theoretical studies including optical trapping [9][10][11][12][13][14]. Such terms also assume greater significance for systems in which electric-dipole couplings are either very small or vanish altogether-when, for example, a relevant electronic transition is electric-dipole forbidden by symmetry.…”

Quantum localization issues in nonlinear frequency conversion and harmonic generation

“…The leading terms in the multipolar expansion of H int are: (2) provides for calculations within the well-known electric-dipole approximation -a constraint adopted in the primary determination of non-local features in nonlinear optics. Higher order couplings become significant when studying chiral discriminatory effects in optical processes including forces [31][32][33] and non-linear optics. [34][35] A quantum field description that gives the correct results for condensed phase materials requires account to be taken of the modification of the fields experienced (and produced) by any specific optical centre(s), due to its surroundings by the other atoms and molecules in the material.…”

Chirality and Chiroptical Effects in Metal Nanostructures: Fundamentals and Current Trends

“…[1] The authors regret this mistake in the article and take the chance to add further references for the readers who might want to go deeper in the subject. [2,3] However, to the best of our knowledge, it is yet unclear to which extent the optical chirality of a field influences the dissymmetry of a chiroptical system in a way that enhances measurable quantities such as circular dichroism (CD), or plasmon resonance shifts in QED frameworks. This correction does not affect the conclusions of the original publication.…”