Longitudinal chirality, enhanced non-reciprocity, and nano-scale planar one-way guiding

TL;DR

This paper introduces a novel planar plasmonic chain with longitudinal chirality that enables one-way guiding and strong non-reciprocity using weaker magnetic fields, suitable for fabrication on a single plane.

Contribution

It presents a new planar structure exhibiting longitudinal chirality and one-way guiding, with enhanced non-reciprocity at lower magnetic field strengths compared to prior work.

Findings

Supports one-way guiding in planar structures

Achieves strong non-reciprocity with weaker magnetic fields

Applicable to both lossless and lossy chains

Abstract

When a linear chain of plasmonic nano-particles is exposed to a transverse DC magnetic field, the chain modes are elliptically polarized, in a single plane parallel to the chain axis; hence, a novel longitudinal plasmon-rotation is created. If, in addition, the chain geometry possesses longitudinal rotation, e.g. by using ellipsoidal particles that rotate in the same plane as the plasmon rotation, strong non-reciprocity is created. The structure possesses a new kind of chirality--the longitudinal chirality--and supports one-way guiding. Since all particles rotate in the same plane, the geometry is planar and can be fabricated by printing leaf-like patches on a single plane. Furthermore, the magnetic field is significantly weaker than in previously reported one-way guiding structures. These properties are examined for ideal (lossless) and for lossy chains.