Dynamical Control of Excitons in Atomically Thin Semiconductors

TL;DR

This paper demonstrates the dynamic electrical control of exciton properties in atomically thin TMD heterostructures, enabling real-time manipulation of emission wavelength and decay rates during exciton lifetime for advanced optoelectronic applications.

Contribution

It introduces a method for dynamical control of excitons in TMDs using electrical fields and patterned gates, a significant advancement over static control techniques.

Findings

Electric fields enable wavelength tuning of exciton emission.

Patterned gates allow rapid local doping and decay rate toggling.

Charge redistribution maps electronic transport in heterostructures.

Abstract

Excitons in transition metal dichalcogenides (TMDs) have emerged as a promising platform for novel applications ranging from optoelectronic devices to quantum optics and solid state quantum simulators. While much progress has been made towards characterizing and controlling excitons in TMDs, manipulating their properties during the course of their lifetime - a key requirement for many optoelectronic device and information processing modalities - remains an outstanding challenge. Here we combine long-lived interlayer excitons in angle-aligned MoSe$_2$/WSe$_2$ heterostructures with fast electrical control to realize dynamical control schemes, in which exciton properties are not predetermined at the time of excitation but can be dynamically manipulated during their lifetime. Leveraging the out-of-plane exciton dipole moment, we use electric fields to demonstrate dynamical control over the exciton emission wavelength. Moreover, employing a patterned gate geometry, we demonstrate rapid local sample doping and toggling of the radiative decay rate through exciton-charge interactions during the exciton lifetime. Spatially mapping the exciton response reveals charge redistribution, offering a novel probe of electronic transport in twisted TMD heterostructures. Our results establish the feasibility of dynamical exciton control schemes, unlocking new directions for exciton-based information processing and optoelectronic devices, and the realization of excitonic phenomena in TMDs.