Site-Controlled Telecom Single-Photon Emitters in Atomically-thin MoTe2

TL;DR

This paper demonstrates the deterministic creation of telecom-range quantum emitters in MoTe2, capable of operating in the O-C bands, with high purity, long lifetimes, and valley degree of freedom access, advancing quantum communication technologies.

Contribution

It reports the first deterministic creation of telecom-band quantum emitters in MoTe2 coupled with nano-pillars, enabling valley DOF access and long photon lifetimes in 2D TMDCs.

Findings

Quantum emitters emit over 1080-1550 nm range.

Photon antibunching with 90% purity at 10 K.

Long lifetimes, 4-6 orders longer than 2D excitons.

Abstract

Quantum emitters (QEs) in two-dimensional transition metal dichalcogenides (2D TMDCs) have advanced to the forefront of quantum communication and transduction research due to their unique potentials in accessing valley pseudo-spin degree of freedom (DOF) and facile integration into quantum-photonic, electronic and sensing platforms via the layer-by-layer-assembly approach. To date, QEs capable of operating in O-C telecommunication bands have not been demonstrated in TMDCs. Here we report a deterministic creation of such telecom QEs emitting over the 1080 to 1550 nm wavelength range via coupling of 2D molybdenum ditelluride (MoTe2) to strain inducing nano-pillar arrays. Our Hanbury Brown and Twiss experiment conducted at 10 K reveals clear photon antibunching with 90% single photon purity. Ultra-long lifetimes, 4-6 orders of magnitude longer than that of the 2D exciton, are also observed. Polarization analysis further reveals that while some QEs display cross-linearly polarized doublets with ~1 meV splitting resulting from the strain induced anisotropic exchange interaction, valley degeneracy is preserved in other QEs. Valley Zeeman splitting as well as restoring of valley symmetry in cross-polarized doublets are observed under 8T magnetic field. In contrast to other telecom QEs, our QEs which offer the potential to access valley DOF through single photons, could lead to unprecedented advantages in optical fiber-based quantum networks.