Single charge control of localized excitons in heterostructures with ferroelectric thin films and two-dimensional transition metal dichalcogenides

TL;DR

This paper demonstrates a nonvolatile method to control localized excitons in 2D TMDCs using ferroelectric polarization, enabling long-term, deterministic charge state manipulation for quantum photonic applications.

Contribution

It introduces a novel ferroelectric polarization control technique for localized excitons in TMDCs, avoiding issues of traditional electrostatic doping methods.

Findings

Achieved deterministic doping of WSe2 via ferroelectric polarization.

Observed neutral and charged LXs in different polarization regions.

Attained ~90% circular polarization in photon emission under high magnetic fields.

Abstract

Single charge control of localized excitons (LXs) in two-dimensional transition metal dichalcogenides (TMDCs) is crucial for potential applications in quantum information processing and storage. However, traditional electrostatic doping method with applying metallic gates onto TMDCs may cause the inhomogeneous charge distribution, optical quench, and energy loss. Here, by locally controlling the ferroelectric polarization of the ferroelectric thin film BiFeO3 (BFO) with a scanning probe, we can deterministically manipulate the doping type of monolayer WSe2 to achieve the p-type and n-type doping. This nonvolatile approach can maintain the doping type and hold the localized excitonic charges for a long time without applied voltage. Our work demonstrated that ferroelectric polarization of BFO can control the charges of LXs effectively. Neutral and charged LXs have been observed in different ferroelectric polarization regions, confirmed by magnetic optical measurement. Highly circular polarization degree about 90 % of the photon emission from these quantum emitters have been achieved in high magnetic fields. Controlling single charge of LXs in a non-volatile way shows a great potential for deterministic photon emission with desired charge states for photonic long-term memory.