English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We analyze the ponderomotive action experienced by a small spherical particleimmersed in an optical field, in relation to the internal energy flows (opticalcurrents) and their spin and orbital constituents. The problem is studiedanalytically, based on the dipole model, and numerically. Three sources of thefield mechanical action - energy density gradient and the orbital and spinparts of the energy flow - differ by the ponderomotive mechanism, and theirphysical nature manifests itself in the optical force dependence on theparticle radius a. If a is much less than the radiation wavelength, the opticalforce behaves as a^n and integer n can be used to classify the sources of themechanical action. This classification correlates with the multipolerepresentation of the field-particle interaction: The gradient force and theorbital-momentum force appear due to the electric or magnetic dipole momentsper se, the spin-momentum force emerges due to interaction between the electricand magnetic dipoles or between the dipole and quadruple moments (if theparticle is polarisable electrically but not magnetically or vice versa). Inprinciple, the spin and orbital currents can be measured separately by theprobe particle motion, employing the special choice of particles with necessarymagnetic and/or electric properties.

Subwavelength particles in an inhomogeneous light field: Optical forces associated with the spin and orbital energy flows