PHELIQS

Check out our latest research paper authored by Elçin Akar, Adeline Grenier, Anne-Marie PAPON, Audrey JANNAUD, martien den Hertog, and Eva Monroy exploring the growth kinetics of Mg-doped GaN using plasma-assisted molecular beam epitaxy. 👉 https://lnkd.in/eAki6pUJ The optimum growth conditions of GaN:Mg are achieved through a delicate balance of substrate temperature, Mg flux, and III/V ratio. At low substrate temperatures, where Ga desorption from the growing surface is negligible, a pronounced self-compensation effect linked to polarity inversion significantly reduces net acceptor concentration. In our study, we focus on high-temperature growth and introduce a method for the in situ determination of the threshold of polarity inversion using the RHEED intensity transient which is caused by Ga desorption from the GaN surface. Using this technique, we demonstrate that polarity inversion depends not only on the Mg flux but also on the substrate temperature and, most critically, on the metal-to-nitrogen ratio, which emerges as the most sensitive parameter. We show that maintaining a substantial excess of Ga within the bilayer regime, while staying just below the threshold for Ga droplet accumulation, is crucial to prevent polarity inversion. This work is the result of a collaboration between the NPSC - Nanophysics and Semiconductors team of PHELIQS - Quantum Photonics, Electronics and Engineering, CEA-Leti and Institut Néel CNRS. #researchpaper #epitaxy #molecularbeamepitaxy #galliumnitride CEA-Irig, Université Grenoble Alpes, Grenoble INP - UGA

Read the new paper by Biel Martinez Diaz, Silvano De Franceschi, and Yann-Michel Niquet studying how to mitigate variability in epitaxial-heterostructure-based spin-qubit devices. 👉 https://lnkd.in/eCrC6WWh The variability in spin-qubit devices based on SiGe epitaxial heterostructures is a significant challenge for the scalability of quantum processors. Variability is primarily caused by charge disorder at the semiconductor-oxide interface, particularly due to charge traps that distort the electrochemical potentials and tunnel coupling in quantum dots. This study explores optimized gate layouts that can mitigate these effects, thereby enhancing the reliability and scalability of spin-qubit devices. This work is the result of a collaboration between CEA-Leti, PHELIQS - Quantum Photonics, Electronics and Engineering and the Modeling and Exploration of Materials (MEM) laboratory of CEA-Irig. #researchpaper #quantum #quantumelectronics #qubits #quantumtechologies CEA-Irig, Université Grenoble Alpes, Grenoble INP - UGA

At PHELIQS, we are happy to be an integral part of the CEA-Irig journey! 🚀 #innovation #research #teamwork

Read the new paper by Alrik Durand, Yoann Baron, Félix Cache, Tobias Herzig, Mario KHOURY, Sebastien Pezzagna, Jan Meijer, Jean-Michel HARTMANN, Shay Reboh, Marco Abbarchi, Isabelle Robert-Philip, Jean-Michel Gérard, Vincent Jacques, Guillaume Cassabois, and Anaïs Dréau studying single 𝐺 centers in carbon-implanted silicon. 👉 https://lnkd.in/epAVaWxf Single color centers recently isolated in carbon-implanted silicon with an emission line at 1.28 𝜇m have so far been identified as a well-known defect called the 𝐺 center. In this paper, the authors demonstrate that these single defects are actually divided into two distinct families, each with specific single-photon properties. On one side are the genuine G centers, and on the other, the faux G centers, which belong to a different defect labeled the G⋆ center.  These results provide a safeguard against future defect misidentifications, which is crucial for the further development of quantum technologies relying on the quantum properties of G or G⋆ centers. This work is the result of a collaboration between the University of Montpellier, Leipzig University, IM2NP CNRS UMR 7334, CEA-Leti, SOLNIL, and the NPSC - Nanophysics and Semiconductors team of PHELIQS - Quantum Photonics, Electronics and Engineering. #researchpaper #quantumphotonics #photonics #nanotechnology #siliconphotonics CEA-Irig, Université Grenoble Alpes, Grenoble INP - UGA

👉 Aujourd'hui Catherine Staron, Vice Présidente déléguée à l'enseignement supérieur, à la recherche et à l'innovation de la Région Auvergne-Rhône-Alpes, a visité notre institut CEA-Irig accompagnée de Jérôme Fraysse, directeur adjoint DESRI et de Gabriele Fioni, recteur délégué à l'enseignement supérieur, à la recherche et à l'innovation. 👍 L'occasion de leur faire découvrir nos activités de recherche et nos enjeux d'innovation sur les programmes - spintronique pour un numérique frugal au laboratoire SPINTEC avec un focus sur nos activités de calcul neuromorphique et de mémoires innovantes avec le projet de la start up Nellow, - technologies quantiques avec un focus sur la filière de qubit semiconducteur au laboratoire PHELIQS - médecine personnalisée avec un focus sur les organoïdes sur puces dans le laboratoire BGE/Biomics. 🙏 Un grand merci pour cette visite et les échanges très fructueux! Lucian Prejbeanu, Silvano De Franceschi, Philippe Talatchian, Emily Tubbs, CEA Grenoble, Jean-Philippe Attané

Une lecture conseillée aux amoureux de la photonique : Notre collègue Jean-Michel Gérard rend hommage à Jean-Yves Marzin, Directeur de Recherche CNRS, avec un article intitulé "1994 : Naissance d’un atome artificiel pour la photonique quantique" dans la revue "Photoniques" de la SFO - SOCIETE FRANCAISE D'OPTIQUE. Dans cet article, nous revenons sur une avancée majeure réalisée en 1994 par l’équipe du CNET Bagneux, dirigée par Jean-Yves Marzin. Pour la première fois, ils ont pu observer le spectre d’émission d’une boîte quantique unique de haute qualité, obtenue par croissance épitaxiale. Cette découverte a ouvert la voie à une multitude d'études spectroscopiques et a établi les bases de l'utilisation des boîtes quantiques en photonique quantique. 📄 L'article, en français, est disponible en accès libre: https://lnkd.in/e9Cz98x9 #photonique #photoniquequantique #recherche #boîtesquantiques CEA-Irig, Université Grenoble Alpes, Grenoble INP - UGA, CNRS NPSC - Nanophysics and Semiconductors

🎉 Congratulations to Antonio Lacerda Santos Neto for the successful defense of his PhD Thesis entitled "Predictive modeling of nanoelectronic devices". The work was supervised by Xavier Waintal and Christoph Groth. This PhD thesis is a cotribution to the control of quantum-mechanical systems in condensed matter, advancing our understanding and development of full-fledged quantum technologies. Their work focused on creating a comprehensive simulation stack, ranging from the microscopic modeling of individual quantum bits and flying qubits to the treatment of many-body correlations with automatic Feynman diagrams calculations, and exploring the collective behavior of multi-qubit devices and quantum error correction codes. A notable achievement of this research is bridging the gap between abstract quantum models and actual physical systems, essential for understanding quantum entanglement and decoherence dynamics. Antonio developed innovative algorithms that simplify models from their microscopic counterparts using renormalization group theory, applied to quantum nanoelectronics and semiconductor circuits. This work addresses long-standing issues like the 0.7 anomaly and modern challenges in building flying qubit architectures. Thanks to Anton Akhmerov, Fabienne Michelini, Rodolfo Jalaber and Hermann Sellier for their participation to the jury. #phdthesis #quantum #quantumtechnologies #quantumcomputing CEA-Irig, Université Grenoble Alpes, Grenoble INP - UGA

Read the new paper by Natthawadi Buatip, Thomas Auzelle, Philipp John, Sander Rauwerdink, Manmeet Kaur Sodhi, Mathieu SALAÜN, bruno fernandez, Eva Monroy, Daniel Mornex, Chris Bowen, and Rudeesun Songmuang demonstrating piezoelectric nanogenerators based on AlN nanowires. 👉 https://lnkd.in/eWXndHtt This study analyzes the direct piezo-response of AlN nanowire-based vertically integrated nanogenerators in relation to mechanical excitation frequency. It demonstrates that piezo-charge, piezo-voltage, and impedance at a given device position correlate through an equivalent circuit model across the frequency range. The results help determine the performance figures of merit for nanowire-based VINGs, specifically the piezoelectric voltage constant (g) for sensing and the product d·g for energy harvesting, where d is the piezoelectric charge constant. The study suggests that nanowires may surpass rigid counterparts like single-crystal GaN, quartz substrates, and sputtered AlN thin films in mechanical sensing and energy generation. This work is the result of a collaboration between the NPSC - Nanophysics and Semiconductors team of Institut Néel CNRS and PHELIQS - Quantum Photonics, Electronics and Engineering, Paul Drude Institute for Solid State Electronics (PDI) and University of Bath. #researchpaper #nanotechnology #nanomaterials #nanowires #aluminiumnitride #galliumnitride #piezogenerator CEA-Irig, CNRS, Université Grenoble Alpes, Grenoble INP - UGA

🎉 Congratulations to Marion Bassi for the successful defense of her PhD Thesis entitled "Tunable resilience to charge noise of a hole spin". The work was supervised by Xavier Jehl and Étienne Dumur. This PhD thesis explored the potential of spin qubits in group-IV semiconductor quantum dots for scalable quantum processors, focusing on hole particles due to their fast and all-electrical manipulation enabled by large spin-orbit coupling. Despite the challenge of environmental interactions degrading qubit coherence time, efforts have identified "sweetspots" of enhanced coherence dependent on magnetic field orientation. The research characterizes electrical noise impacts on a single hole spin qubit in a P-doped silicon-MOS structure, finding that these sweetspots form continuous "sweetlines" around magnetic field polar-angle components. Experimentally, sweetline operation demonstrates extended coherence times and efficient electric-dipole spin resonance with high Rabi frequencies and quality factors. The study highlights significant gate-voltage control of sweetlines, relevant for scalability, and extends the investigation to a two-qubit system, emphasizing the importance of tuning sweetlines in spin qubit systems. Thanks to Alexander Hamilton, Georgios Katsaros, Arne Laucht, David FERRAND, Maximilian Rimbach, and Hélène Béa for their participation to the jury. #phdthesis #quantum #quantumtechnologies #qubits CEA-Irig, Université Grenoble Alpes, Grenoble INP - UGA

🎉 Today, our NPSC - Nanophysics and Semiconductors team celebrated their annual NPSC Day!