Non-hermitian 2D materials based on the nonlinear Hall effect

Abstract

Symmetries and broken symmetries play important roles in physics. In particular, they constrain the electromagnetic response of materials and the allowed light-matter interactions. In such a context, symmetry breaking can lead to unique and peculiar physical phenomena. The Hall effects, for example, result from broken symmetries. In the usual linear Hall effects, the time-reversal symmetry is broken by a magnetic bias. Alternatively, nonlinear Hall effects can occur in systems with a broken inversion symmetry rather than broken time-reversal symmetry. Here we explore several physical platforms that can enable nonreciprocal and non-Hermitian responses based on the nonlinear Hall effect and 2D material layers biased with a static electric field. It will be shown that the electric field bias may create unique physical responses, including regimes of loss and gain controlled by the wave-polarization, asymmetric responses, and others. In this talk, we will present an overview of our on-going work on this topic.