Out-of-equilibrium layer electric phases in van der Waals multilayers

Dielectric screening in insulators often counteracts an applied displacement field, reducing the total electric field that electrons experience. This ubiquitous screening property is intimately tied to the equilibrium distribution of electrons. In this talk, we discuss how this behavior can be transformed when materials are pushed out-of-equilibrium. In particular, we will discuss how electrons pushed far out-of-equilibrium in layered materials (e.g., van der Waals heterostructures) can naturally display anti-screening behavior: i.e. the layer electric polarization is opposite to the total electric field sustained across layers. When pushed to the extreme, such layer polarizations can become self-induced, exhibiting multiple self-consistent phases of out-of-plane electric dipole (and concomittant with an energy gap) for a single applied displacement field. Strikingly multiple steady states persist even for zero applied displacement field. These out-of-equilibrium layer electric phases can provide on-demand means of controlling electric polarizations in layered materials.