10th ASCENT+ Newsletter – February 2024
Contents
Two Successful Research Accelerators at CEA-Leti & INL
2023 seems already so far away, but let’s go back a little and take a look at the end of the year. How about delving into the last two Research Accelerator events?
Last November, CEA Leti (France) hosted junior researchers to learn more about nanoelectronics and the technologies they can use to advance their own work using ASCENT+ later on.
Six participants – PhD and junior researchers – from Belgium, Spain, Italy and Romania were invited to discover the nanocharacterisation platform at the CEA-Leti in Grenoble. The CEA staff welcomed them and showed us around, giving precious insights on how to use some tools and how they could be used to solve challenges the junior researchers were facing in their work.
It was followed by the International Iberian Nanotechnology Laboratory (INL) in Portugal in January which organised their first ASCENT+ training event on January 24-25. Six applicants, all PhD and early career researchers, were invited for two days in the city of Braga to discover the lab and facilities of INL, a key player in the world of nanotechnologies.
But who can tell better than they did how this experience was and what it brought them?
New ASCENT+ User Testimonial
Muireann de hÓra, PhD student at the University of Cambridge, visited Tyndall recently to do research on her PhD thesis, under the guidance of local Tyndall researcher Dr. Lynette Keeney.
In a short video-testimonial, Muireann tells us about her research and how the ASCENT+ experience went, from the very first contact up to the work with Dr Lynette Keeney.
We hope Muireann had a good experience at Tyndall and that this research will prove useful, with new publications around the corner and a formidable thesis defence!
Discover ASCENT+ User Testimonials in a Webinar
Do you want to know more about ASCENT+, how to get a free-of-charge (EU funded) access to all our available technologies at Tyndall, CEA-Leti, INL, Fraunhofer and imec? Are you interested to know what kind of results you can expect through this EU programme?
Join us for a free webinar on March 6th to discuss of ASCENT+ success stories and testimonials from the ASCENT+ project – presentations from Chipmetrics, Polyn Technology, Liverpool University and others.
Joint Research Activities Lead to Publications
Since the last newsletter, many new publications were added on our website, both for successful projects led with the help of a technology available through ASCENT+, and others in the framework of ASCENT+ cooperation – the Joint Research Activities (JRA).
JRA are crossed-research accomplished between ASCENT+ partners on several themes, with the aim to collaborate to respond to modern challenges in nanoelectronics.
Hyperfine interaction limits polarization entanglement of photons from semiconductor quantum dots
C. Schimpf, F. Basso Basset, M. Aigner, W. Attenender, L. Ginés, G. Undeutsch, M. Reindl, D. Huber, D. Gangloff, E.A. Chekhovich, C. Schneider, C. Höfling, A. Predojević, R. Trotta, and A. Rastelli, “Hyperfine interaction limits polarization entanglement of photons from semiconductor quantum dots”, Physics Review B, 108, L081405 (Aug 2023)
DOI: 10.1103/PhysRevB.108.L081405 (Open Access)
“Excitons in quantum dots are excellent sources of polarization-entangled photon pairs, but a quantitative understanding of their interaction with the nuclear spin bath is still missing. Here we investigate the role of hyperfine energy shifts using experimentally accessible parameters and derive an upper limit to the achievable entanglement fidelity. Our results are consistent with all available literature, indicate that spin noise is often the dominant process limiting the entanglement in InGaAs quantum dots, and suggest routes to alleviate its effect.”
Compact chirped fiber Bragg gratings for single-photon generation from quantum dots 
V. Remesh, R.G. Krämer, R. Schwarz, F. Kappe, Y. Karli, M.P. Siems, T.K. Bracht, S.F. Covre da Silva, A. Rastelli, D.E. Reiter, D. Richter, S. Nolte, and G. Weihs, “Compact chirped fiber Bragg gratings for single-photon generation from quantum dots”, APL Photonics, 8, 101301 (Oct 2023)
DOI: 10.1063/5.0164222 (Open Access)
“A scalable source of single photons is a key constituent of an efficient quantum photonic architecture. To realize this, it is beneficial to have an ensemble of quantum emitters that can be collectively excited with high efficiency. Semiconductor quantum dots hold great potential in this context due to their excellent photophysical properties. Spectral variability of quantum dots is commonly regarded as a drawback introduced by the fabrication method. However, this is beneficial to realize a frequency-multiplexed single-photon platform. Chirped pulse excitation, relying on the so-called adiabatic rapid passage, is the most efficient scheme to excite a quantum dot ensemble due to its immunity to individual quantum dot parameters. Yet, the existing methods of generating chirped laser pulses to excite a quantum emitter are bulky, lossy, and mechanically unstable, which severely hampers the prospects of a quantum dot photon source. Here, we present a compact, robust, and high-efficiency alternative for chirped pulse excitation of solid-state quantum emitters. Our simple plug-and-play module consists of chirped fiber Bragg gratings, fabricated via femtosecond inscription, to provide high values of dispersion in the near-infrared spectral range, where the quantum dots emit. We characterize and benchmark the performance of our method via chirped excitation of a GaAs quantum dot, establishing high-fidelity single-photon generation. Our highly versatile chirping module coupled to a photon source is a significant milestone toward realizing practical quantum photonic devices.”
Meet Dmitri Petrovykh and Discover INL Offers
Dmitri Petrovykh, corporate expert at INL Portugal, gives you an overview of what INL can offer you through the ASCENT+ programme. From Nano for Quantum Technologies to disruptive devices and advanced integration, find out which infrastructure could match your needs.
Previous Issues:
Oct 2023 | Jul 2023 | Feb 2023 | Sep 2022 | May 2022 | Jan 2022 | Sep 2021 | Jul 2021 | Mar 2021
Jul 2019 / Apr 2019 / Jan 2019 / Oct 2018 / Jul 2018 / Apr 2018 / Jan 2018 / Oct 2017 / Jul 2017 / Apr 2017 / Jan 2017 / Sep 2016 / Jun 2016 / Feb 2016
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreements 871130 and 654384.