Integrated on-chip quantum light sources on a van der Waals platform

TL;DR

This paper presents a van der Waals platform integrating quantum emitters, waveguides, and grating couplers on a chip, enabling efficient on-chip single-photon sources for scalable quantum photonic technologies.

Contribution

It introduces a novel van der Waals-based integrated platform combining strain-engineered WSe$_2$ quantum emitters with WS$_2$ waveguides, demonstrating high-purity, waveguide-coupled single-photon emission.

Findings

Achieved high-purity single-photon emission with $g^{(2)}(0) \,=\\, 0.003$ off-chip.

Measured waveguide-coupled single-photon count rate of approximately 1.7 MHz.

Demonstrated efficient integration of quantum light sources on a van der Waals platform.

Abstract

Scalable photonic quantum information technologies require a platform combining quantum light sources, waveguides, and detectors on a single chip. Here, we introduce a van der Waals platform comprising strain-engineered bilayer WSe$_2$ quantum emitters, integrated on multimode WS$_2$ waveguides with optimized grating couplers, enabling efficient on-chip quantum light sources. The emitters exhibit bright, highly polarized emission that couples efficiently into WS$_2$ waveguides. Under resonant p-shell excitation, we observe high-purity, waveguide-coupled single-photon emission, measured using both an off-chip Hanbury Brown-Twiss configuration ($g^{(2)}(0) = 0.003^{+0.030}_{-0.003}$) and an on-chip configuration ($g^{(2)}(0) = 0.076\pm0.023$). For a single output, the out-coupled single-photon count rate at the first lens reaches approximately 320 kHz under continuous-wave p-shell excitation, corresponding to an estimated waveguide-coupled rate of 1.7 MHz. These results demonstrate an efficient, integrated single-photon source and establish a pathway toward scalable photonic quantum information processing centered around nanoengineered van der Waals materials.