An active metasurface enhanced with moir\'e ferroelectricity

TL;DR

This paper demonstrates that ferroelectric moiré domains in twisted hexagonal boron nitride can modulate and control light emission from an adjacent MoSe2 monolayer, enabling dynamic, electrically tunable active metasurfaces with potential for advanced nanophotonics.

Contribution

It introduces a novel approach of using ferroelectric moiré domains to actively control light emission in 2D heterostructures, surpassing traditional moiré systems.

Findings

Ferroelectric moiré domains modulate exciton confinement and emission.

Electrically gated ferroelectric domains enable dynamic control of light emission.

Spectral separation of excitons at domains and domain walls due to Stark shift.

Abstract

Semiconductor moir\'e systems, characterized by their periodic spatial light emission, unveil a new paradigm of active metasurfaces. Here, we show that ferroelectric moir\'e domains formed in a twisted hexagonal boron nitride (t-hBN) substrate can modulate light emission from an adjacent semiconductor MoSe$_2$ monolayer, enhancing its functionality as an active metasurface. The electrostatic potential at the surface of the t-hBN substrate provides a simple way to confine excitons in the MoSe$_2$ monolayer. The excitons confined within the domains and at the domain walls are spectrally separated due to a pronounced Stark shift. Moreover, the patterned light emission can be dynamically controlled by electrically gating the ferroelectric domains, introducing a novel functionality beyond conventional semiconductor moir\'e systems. Our findings chart an exciting pathway for integrating nanometer-scale moir\'e ferroelectric domains with various optically active functional layers, paving the way for advanced nanophotonic applications.