Independent Operation of Two Waveguide-Integrated Quantum Emitters

Abstract

Scaling up single-photon sources directly on a chip is a fundamental requirement for realizing quantum information protocols that demand scalable, integrated photonic qubits. Integrating multiple quantum emitters in a circuit has encountered major roadblocks in wavelength disparity and the lack of a compact excitation method. The authors demonstrate simultaneous excitation of two quantum dots in the same circuit and independent control of the emitters' wavelengths, enabling two-photon quantum interference. Spectral diffusion is not as detrimental to the interference process as anticipated. These results address a longstanding challenge in quantum photonics.