arXiv subjects

Alexander M. Holmes

Publications and source records attributed to Alexander M. Holmes.

3 recordsLinked to original sources

arXiv2022

Automatic Measurement Technique of Electromagnetic Rotation in a Nonreciprocal Medium

This article aims at developing a simple, automated test bench procedure to measure polarization rotation of an electromagnetic wave upon propagation through a nonreciprocal medium. A comprehensive measurement approach is developed from the scattering matrix. The proposed measurement procedure is demonstrated using an electronically tunable nonreciprocal metamaterial, and the accuracy of the proposed method is compared with the well-accepted conventional measurement technique.

physics.app-ph↗

arXiv2020

Exchange splitting and exchange-induced non-reciprocal photonic behavior of graphene in CrI3-graphene vdW heterostructures

The exchange splitting and resulting electromagnetic response of graphene in a monolayer chromium triiodide(CrI3) graphene van der Waals(vdW) heterostructure are considered using a combination of density functional theory and electromagnetic calculations. Although the effective exchange fields are in the hundreds of Tesla, for the equilibrium separation non reciprocal effects are found to be weak compared to those for a comparable external magnetic bias. For non equilibrium separations, nonreciprocal effects can be substantial.

cond-mat.mes-hall↗

arXiv2019

Robust surface plasmon polaritons on gyrotropic interfaces

Unidirectional surface plasmon polaritons (SPPs) at the interface between a gyrotropic medium and a simple medium are studied in a newly-recognized frequency regime wherein the SPPs form narrow, beam-like patterns due to hyperbolic dispersion. The SPP beams are steerable by controlling parameters such as the cyclotron frequency (external bias) or the frequency of operation. The bulk band structure along different propagation directions is examined to ascertain a common bandgap, valid for all propagation directions, which the SPPs cross. The case of a finite-thickness gyrotropic slab is also considered, for which we present the Green function and examine the thickness and loss level required to maintain a unidirectional SPP.

physics.optics↗