Three components on one chip

Photonic circuit in which single photons are emitted, guided and split into two waveguide-arms. University of Stuttgart/Mario Schwartz

Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is based on the utilization of single photons to carry and process quantum information.

Scientists of the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) were now able to integrate three necessary main components (single-photon source, beamsplitters and single-photon detectors) on a single chip and operate it on the single-photon level.

This experiment demonstrates the functionality of the basic components for a scalable system for photon-based quantum information processes. The results got published in Nano Letters.

In contrast to the widespread silicon technology, the experiment was implemented on a gallium arsenide (GaAs) platform, allowing the direct integration of nanometer-sized structures, called quantum dots (QDs), which can serve as efficient on-demand sources of single photons.

In addition, GaAs allows guiding these single photons to optical logic circuits and to special on-chip detectors made of superconducting nanowires. In the experiment, single photons emitted by an optically pumped quantum dot were guided inside a photonic waveguide and divided by an on-chip beamsplitter into two waveguide-arms, each equipped with a detector.

“One of the challenges so far in this type of fully on-chip experiment was the close proximity of the excitation laser to the on-chip detectors”, explains Mario Schwartz.

The PhD student from the Institute of Semiconductor Optics and Functional Interfaces (IHFG), University of Stuttgart, was working over the last years on the realization of a proof-of-principle experiment to show the feasibility of combining all main components on one single photonic chip.

The project was realized in close collaboration with the PhD student Ekkehart Schmidt from the KIT, who is an expert for the design and implementation of the on-chip detectors. “The detectors cannot distinguish photons coming from the laser and photons coming from the quantum dot, leading to undesirable detection events”, Schmidt further points out.

The scientists were able to significantly reduce the influence of the laser photons by implementing reflecting metal layers on the chip. This idea allowed the verification of the quantum nature of the QD emission by using only the on-chip components.

“The successful experiment is an important step forward and demonstrates the potential of fully integrated photonic circuits with all main components being implemented on a single chip. We foresee clear possibilities of increasing the device complexity in the near future” says Prof. Dr. Peter Michler, director of the IHFG, University of Stuttgart.

Prof. Dr. Peter Michler, Mario Schwartz, Florian Hornung, University of Stuttgart, Institute of Semiconductor Optics and Functional Interfaces (IHFG), Tel.:+49 (0)711/685-64660, p.michler@ihfg.uni-stuttgart.de

Mario Schwartz, Ekkehart Schmidt, Ulrich Rengstl, Florian Hornung, Stefan Hepp, Simone L. Portalupi, Konstantin llin, Michael Jetter, Michael Siegel, and Peter Michler: Fully On-Chip Single-Photon Hanbury-Brown and Twiss Experiment on a Monolithic Semiconductor–Superconductor Platform, Nano Letters, 2018, 18 (11), pp 6892–6897

https://pubs.acs.org/doi/10.1021/acs.nanolett.8b02794

Media Contact

Andrea Mayer-Grenu idw - Informationsdienst Wissenschaft

Alle Nachrichten aus der Kategorie: Information Technology

Here you can find a summary of innovations in the fields of information and data processing and up-to-date developments on IT equipment and hardware.

This area covers topics such as IT services, IT architectures, IT management and telecommunications.

Zurück zur Startseite

Kommentare (0)

Schreib Kommentar

Neueste Beiträge

Ionic Defect Landscape in Perovskite Solar Cells Revealed

Joint research work between Chemnitz University of Technology and the Technical University of Dresden under Chemnitz leadership reveals ionic defect landscape in metal halide perovskites – publication in renowned journal…

Nanomaterials enable dual-mode heating and cooling device

Device could cut HVAC energy use by nearly 20% in the US. Engineers at Duke University have demonstrated a dual-mode heating and cooling device for building climate control that, if…

What social distancing does to a brain

Scientists discover a neuropeptide that reflects the current state of a fish’s social environment. Have you recently wondered how social-distancing and self-isolation may be affecting your brain? An international research…

By continuing to use the site, you agree to the use of cookies. more information

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.

Close