Electrical Charge Control of h-BN Single Photon Sources

TL;DR

This paper demonstrates electrical control of single photon emission from h-BN quantum emitters by tuning their charge state via an external electric field, advancing quantum photonic applications.

Contribution

It introduces a method to electrically switch h-BN quantum emitters' photoluminescence by controlling their charge state through a nearby graphene layer.

Findings

Electrical switching of h-BN photoluminescence achieved.

Charge transition levels of quantum emitters identified.

Complete on-off emission control demonstrated.

Abstract

Colour centres of hexagonal boron nitride (h-BN) have been discovered as promising and practical single photon sources due to their high brightness and narrow spectral linewidth at room-temperature. In order to realize h-BN based photonic quantum communications, the ability to electrically activate the single photon fluorescence using an external electric field is crucial. In this work, we show the electrical switching of the photoluminescence from h-BN quantum emitters, enabled by the controllable electron transfer from the nearby charge reservoir. By tuning the Fermi level of graphene next to the h-BN defects, we observed luminescence brightening of a quantum emitter upon the application of a voltage due to the direct charge state manipulation. In addition, the correlation measurement of the single photon sources with the graphene's Raman spectroscopy allows us to extract the exact charge transition level of quantum emitters, providing the information on the crystallographic nature of the defect structure. With the complete on-off switching of emission intensity of h-BN quantum emitters using a voltage, our result paves the way for the van der Waals colour centre based photonic quantum information processing, cryptography and memory applications.