Nonreciprocity in “motion”

Lorentz reciprocity is intimately related to the linearity and invariance of Maxwell’s equations under time-reversal symmetry, and forbids one-way light flows in standard metal-dielectric platforms. Indeed, reciprocal systems are inherently bidirectional. Asymmetric light flows are typically obtained using a static magnetic bias.

In this talk, we will highlight that nonreciprocity and mechanical motion are deeply intertwined. We will discuss some unusual features of the electrodynamics of moving media [1] and highlight that a translational motion can be mimicked with a drift-current [2]. In particular, we will show that a graphene sheet biased with a direct electric current is a very promising solution to break the Lorentz reciprocity and have a broadband regime of unidirectional propagation of surface plasmons protected against backscattering from obstacles and imperfections [3].

[1] M. G. Silveirinha, Phys. Rev. X, 4, 031013, (2014).
[2] T. A. Morgado, M. G. Silveirinha, Phys. Rev. Lett. 119, 133901 (2017).
[3] T. A. Morgado, M. G. Silveirinha, http://dx.doi.org/10.1021/acsphotonics.8b00987, ACS Photonics, (2018) (in press).