Transverse spin and momentum in two-wave interference
Abstract
We analyze the interference field formed by two electromagnetic plane waves (with the same frequency but different wave vectors), and find that such field reveals a rich and highly non-trivial structure of the local momentum and spin densities. Despite the seemingly-planar and extensively-studied character of the two-wave system, we find that it possesses a transverse (out-of-plane) helicity-independent spin density, and also a transverse polarization-dependent momentum density with unusual physical properties. The polarization-dependent transverse momentum represents the so-called Belinfante spin momentum, which does not exert the usual optical pressure and it is considered as `virtual' in field theory. We perform analytical estimations and exact numerical simulations of the interaction of the two-wave field with probe Mie particles. The results of these calculations clearly indicate the straightforward detectability of the unusual spin and momentum properties in the two-wave field and strongly motivate their future experimental verifications.
Cite
@article{arxiv.1407.6786,
title = {Transverse spin and momentum in two-wave interference},
author = {Aleksandr Y. Bekshaev and Konstantin Y. Bliokh and Franco Nori},
journal= {arXiv preprint arXiv:1407.6786},
year = {2015}
}
Comments
13 pages, 4 figures, Supplementary Information, to appear in Phys. Rev. X