Quantum formulation for nanoscale optical and material chirality: symmetry issues, space and time parity, and observables

Abstract

To properly represent the interplay and coupling of optical and material chirality at the photonmolecule or photon-nanoparticle level invites a recognition of quantum facets in the fundamental aspects and mechanisms of light-matter interaction. It is therefore appropriate to cast theory in a general quantum form, one that is applicable to both linear and nonlinear optics as well as various forms of chiroptical interaction including chiral optomechanics. Such a framework, fully accounting for both radiation and matter in quantum terms, facilitates the scrutiny and identification of key issues concerning spatial and temporal parity, scale, dissipation and measurement. Furthermore it fully provides for describing the interactions of structured or twisted light beams with a vortex character, and it leads to the complete identification of symmetry conditions for materials to provide for chiral discrimination. Quantum considerations also lend a distinctive perspective to the very different senses in which other aspects of chirality are recognized in metamaterials. Duly attending to the symmetry principles governing allowed or disallowed forms of chiral discrimination supports an objective appraisal of the experimental possibilities and developing applications.

Interaction of light carrying orbital angular momentum with a chiral dipolar scatterer

“…The corresponding field couples preferentially to the nanohelix's fundamental chiral mode if the sign of the optical chirality in the focal field (dictated by the vorticity of the input field) matches that of the relative phase between the electric and magnetic components of the nanohelix's chiral mode (dictated by the helix's handedness). In contrast to recent studies [21,22], the vorticity of the incoming beam was sensed via dipolar interactions not involving any higher order multipoles. To prove our concept experimentally, we investigated the differential transmission of LG ±1 0 beams tightly focused onto a single plasmonic nanohelix.…”

Spin-orbit interactions and chiroptical effects engaging orbital angular momentum of twisted light in chiral and achiral media

“…Conversely, in systematically ordered media, (whether the orientational ordering is total or partial), a lack of full rotational symmetry means that chiroptical effects can be anticipated in either chiral or achiral samples [52][53][54]. As was observed in Section III, E1E2 terms cannot contribute to chiroptical effects in isotropic chiral or achiral media.…”

Transmission of classically entangled beams through mouse brain tissue

“…For a future project we plan to do brain transmission and imaging on a human brain with Alzheimer's disease, focusing on areas that are mainly affected such as hippocampus, cingulate gyrus, and amygdala [36]. In addition, Forbes and Andrews [15][16][17][18] showed dipole and quadrupole have a chiroptical effect associated with OAM with circular dichroism (left and right circular polarization). Afanasev et al [37] have shown that higher multipole transitions exhibit circular dichroism with OAM (ℓ) dependency, in non-chiral atomic matter.…”

“…This chiral medium will interact with the electromagnetic field of light by changing its state of polarization; this effect makes the brain a chiral bio-plasma [14]. Structured vector light is expected to interact with chiral matter by coupling with electric dipole, magnetic dipole and quadrupole moments and transitions from Fermi Golden Rule [15][16][17][18]. The underlying unique and complex structure and properties make the brain a "smart tissue"; due to this heterogeneity in the brain, different regions could show dissimilar effects.…”

“…Our goals are to observe if there is a direct proportionality between the OAM(ℓ) and the transmission, and chiroptical interactions between a targeted region in the brain and each polarization used. Chiroptical effects involve interplay of chirality of molecular and electromagnetic radiation to produce energy shifts to the handedness of circular polarized photons such as circular dichroism in solids, liquids and biofluids [14][15][16][17][18].…”