Nonreciprocal and Non-Hermitian Material Response Inspired Semiconductor Transistors

Here, inspired by the operation of conventional semiconductor transistors, we introduce a novel class of bulk materials with nonreciprocal and non-Hermitian electromagnetic response. Our analysis shows that material nonlinearities combined with a static electric bias may lead to a linearized permittivity tensor that lacks the Hermitian and transpose symmetries. Remarkably, the material can either dissipate or generate energy, depending on the relative phase of the electric field components. We introduce a simple design for an electromagnetic isolator based on an idealized MOSFET-metamaterial and show that its performance can in principle surpass conventional Faraday isolators due to the material gain. Furthermore, it is suggested that analogous material responses may be engineered in natural media in nonequilibrium situations. Our solution determines an entirely novel paradigm to break the electromagnetic reciprocity in a bulk nonlinear material using a static electric bias.

Automated summary

Inspired by semiconductor transistors, this study introduces a novel class of bulk materials with nonreciprocal and non-Hermitian electromagnetic response. The linearized permittivity tensor lacks Hermitian and transpose symmetries due to material nonlinearities combined with a static electric bias. By using an idealized MOSFET-metamaterial, an electromagnetic isolator is designed that can potentially outperform conventional Faraday isolators due to material gain. It is also suggested that similar material responses can be engineered in natural media in nonequilibrium situations.