Integrated superconducting detectors on semiconductors for quantum optics applications

TL;DR

This paper reviews advancements in integrating superconducting niobium nitride detectors on semiconductor substrates, enabling efficient, ultrafast quantum photonic circuits with on-chip quantum dot detection and resonance fluorescence generation.

Contribution

It presents novel methods for growing, patterning, and integrating superconducting detectors on semiconductors, achieving high efficiency and ultrafast detection in quantum photonic circuits.

Findings

Detection quantum efficiency up to 20%

Single photon timing resolution <72 ps

On-chip generation of resonance fluorescence

Abstract

Semiconductor quantum photonic circuits can be used to efficiently generate, manipulate, route and exploit non-classical states of light for distributed photon based quantum information technologies. In this article, we review our recent achievements on the growth, nanofabrication and integration of high-quality, superconducting niobium nitride thin films on optically active, semiconducting GaAs substrates and their patterning to realise highly efficient and ultrafast superconducting detectors on semiconductor nanomaterials containing quantum dots. Our state-of-the-art detectors reach external detection quantum efficiencies up to 20% for ~4nm thin films and single photon timing resolutions <72ps. We discuss the integration of such detectors into quantum dot loaded, semiconductor ridge waveguides, resulting in the on-chip, time-resolved detection of quantum dot luminescence. Furthermore, a prototype quantum optical circuit is demonstrated that enabled the on-chip generation of resonance fluorescence from an individual InGaAs quantum dot, with a line width <15 $\mu$eV displaced by 1mm from the superconducting detector on the very same semiconductor chip. Thus, all key components required for prototype quantum photonic circuits with sources, optical components and detectors on the same chip are reported.