Biomedical Engineering Reference
In-Depth Information
Chapter 6
Chiral Surface Plasmon Polaritons on
One-Dimension Nanowires
Shunping Zhang
a
and Hongxing Xu
a,b
a
Center for Nanoscience and Nanotechnology, and School of Physics and Technology,
Wuhan University, Wuhan 430072, China
b
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics,
Chinese Academy of Sciences, Beijing, Box 603-146, 100190, China
hxxu@iphy.ac.cn
6.1 Introduction
An object is chiral when it is not identical to its mirror image. For
electromagnetic waves, circularly polarized plane waves are chiral
inthesensethateach“enantiomer”carriesanoppositespinangular
momentum. The interactions of chiral objects with left- or right-
handed chiral electromagnetic waves are different, giving rise to
the circular dichroism (CD) that can serve as a measurement of the
chirality of the object. For most natural molecules or biomolecules,
CD is typically about 10
−
2
(electronic) or 10
−
4
∼
10
−
6
(vibrational)
compared with their parent signals [1]. Although the CD signals
of most natural molecules occur in the ultraviolet (UV) range,
rationally designed chiral “meta-atoms” and “meta-molecules” have
