arXiv:2210.09826 · Physical Review Applied

Independent Operation of Two Waveguide-Integrated Quantum Emitters

Camille Papon, Yujing Wang, Ravitej Uppu, S. Scholz, Andreas Dirk Wieck, Arne Ludwig, Peter Lodahl, Leonardo Midolo

Published Jun 27, 2023• 29 citations

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.

DOI: 10.1103/physrevapplied.19.l061003

Related papers

Scalable Quantum Interference from Indistinguishable Quantum Dots

Sheena Shaji, Suraj Goel, Julian Wiercinski +7 more

Quantum interference of indistinguishable photons is the foundation of photonic quantum technologies, yet scaling from a few to many identical quantum light sources remains a major challenge. In solid-state platforms, spatial and spectral inhomogeneity and resource-intensive architectures impede scaling. As a result, interference between remote, independent quantum emitters has been thus far limited to pairs. Here we introduce a wavefront-shaping approach that enables scalable interference from multiple indistinguishable quantum dots on the same chip. Using programmable spatial light modulators, we independently excite, collect, and route emission from spatially distinct, yet spectrally degenerate dots. Scaling from two to five indistinguishable emitters, we verify interference through cooperative-emission phenomena and Hong-Ou-Mandel two-photon interference, thereby establishing a route towards large-scale, programmable quantum photonic architectures.

quant-pharXiv:2603.25684Mar 27, 20260 citations

On-Chip Hong–Ou–Mandel Interference from Separate Quantum Dot Emitters in an Integrated Circuit

Łukasz Dusanowski, Dominik Köck, Christian Schneider +1 more

Scalable quantum photonic technologies require the low-loss integration of many identical single-photon sources with photonic circuitry on a chip. Relatively complex quantum photonic circuits have already been demonstrated; however, sources used so far relied on parametric down-conversion which has a probabilistic nature that intrinsically limits its efficiency and scalability. Quantum emitter-based single-photon sources are free of this limitation, but frequency matching of multiple emitters within a single circuit remains challenging. In this work, we demonstrate a key component in this regard in the form of a fully monolithic GaAs circuit combining two frequency-matched quantum dot single-photon sources interconnected with a low-loss on-chip beamsplitter connected via single-mode ridge waveguides. This device enabled us to perform a two-photon interference experiment on-chip with a visibility reaching 66%. Our device could be further scaled up, providing a clear path to increasing the complexity of quantum circuits toward fully scalable integrated quantum technologies.

arXiv:2301.01706ACS PhotonicsJun 21, 202327 citations

A programmable quantum photonic platform integrating coherent emitters

Hanna Salamon, Mikkel T. Mikkelsen, Zhe Liu +4 more

Photonic quantum technologies require the integration of high-quality quantum light sources with programmable photonic circuitry to enable on-chip quantum information processing. Semiconductor quantum dots have emerged as a leading platform for quantum light generation, yet their monolithic integration with cryogenic-compatible, programmable photonic circuitry remains challenging. Here we demonstrate a programmable quantum photonic platform that enables simultaneous control of highly coherent quantum dot-based single photon emitters and reconfigurable optical elements at cryogenic temperatures. System-level integration enables individual electrical and optical addressing of active components on a single chip, allowing their concurrent operation while preserving coherent non-classical light emission. We demonstrate multiple quantum-photonic functionalities, including pure single-photon generation, two-photon interference, and resonant transmission and reflection measurements of integrated emitters. These results mark a step from isolated quantum-optical devices towards programmable quantum-photonic hardware platforms capable of combining coherent quantum emitters with large-scale photonic functionality.

quant-pharXiv:2610.06451Oct 6, 20260 citations

Super-Radiant Emission from Quantum Dots in a Nanophotonic Waveguide

Je‐Hyung Kim, Shahriar Aghaeimeibodi, Christopher J. K. Richardson +2 more

Future scalable photonic quantum information processing relies on the ability of integrating multiple interacting quantum emitters into a single chip. Quantum dots provide ideal on-chip quantum light sources. However, achieving quantum interaction between multiple quantum dots on-a-chip is a challenging task due to the randomness in their frequency and position, requiring local tuning technique and long-range quantum interaction. Here, we demonstrate quantum interactions between separated two quantum dots on a nanophotonic waveguide. We achieve a photon-mediated long-range interaction by integrating the quantum dots to the same optical mode of a nanophotonic waveguide and overcome spectral mismatch by incorporating on-chip thermal tuners. We observe their quantum interactions of the form of super-radiant emission, where the two dots collectively emit faster than each dot individually. Creating super-radiant emission from integrated quantum emitters could enable compact chip-integrated photonic structures that exhibit long-range quantum interactions. Therefore, these results represent a major step toward establishing photonic quantum information processors composed of multiple interacting quantum emitters on a semiconductor chip.

arXiv:1804.03631Nano LettersJul 2, 2018121 citations

Integrated nanophotonics for the development of fully functional quantum circuits based on on-demand single-photon emitters

Sven Rodt, Stephan Reitzenstein

In recent years, research on integrated quantum circuits has developed rapidly and exciting results have been achieved. The overarching goal of this emerging research direction in the field of modern quantum technology is the scalable integration of quantum functionality on robust chips. Such chips can work independently of one another, but it is even more interesting to develop them modularly for integration into larger quantum networks, thereby linking quantum computation and quantum communication in the same framework. In this context, the ongoing development and further optimization of integrated quantum circuits aim, inter alia, to achieve a quantum advantage in the area of quantum computing and to pave the way for multipartite quantum networks. The functionality of such chips is essentially based on single-photon operations, such as interference at beam splitters in combination with phase shifters in the field of linear optical quantum computing and Bell-state measurements for entanglement swapping in long-distance quantum networks. While individual functionalities such as CNOT gates and more complex quantum computing operations such as boson sampling in a combination of waveguide chips and external photon sources and detectors were successfully demonstrated, the field is currently facing the major challenge of integrating all necessary components monolithically on chip in order to exploit the full potential of integrated quantum nanophotonics. The present Perspective discusses the status and the present challenges of integrated quantum nanophotonics based on on-demand single-photon emitters and gives an outlook on required developments to enter the next level of fully functional quantum circuits for photonic quantum technology.

APL PhotonicsJan 1, 202155 citations

Quantum Interference of Identical Photons from Remote Quantum Dots

Liang Zhai, Giang N. Nguyen, Clemens Spinnler +6 more

Photonic quantum technology provides a viable route to quantum communication, quantum simulation, and quantum information processing. Recent progress has seen the realisation of boson sampling using 20 single-photons and quantum key distribution over hundreds of kilometres. Scaling the complexity requires photonic architectures containing a large number of single photons, multiple photon-sources and photon-counters. Semiconductor quantum dots are bright and fast sources of coherent single-photons. For applications, a significant roadblock is the poor quantum coherence upon interfering single photons created by independent quantum dots. Here, we demonstrate two-photon interference with near-unity visibility using photons from remote quantum dots. Exploiting the quantum interference, we demonstrate a photonic controlled-not circuit and a high-fidelity entanglement between photons of different origins. Our results provide a long-awaited solution to the challenge of creating coherent single-photons in a scalable way. In the near future, they point to a demonstration of quantum advantage using quantum-dot single photons and an implementation of device-independent quantum key distribution.

Jun 7, 20218 citations