PHELIQS - Quantum Photonics, Electronics and Engineering’s Post

Read the new paper by Baptiste Lefaucher, Jean-Baptiste Jager, Vincent Calvo, Félix Cache, Alrik Durand, Vincent Jacques, Isabelle Robert-Philip, Guillaume Cassabois, Yoann Baron, Frédéric MAZEN, PhD, Sebastien Kerdiles, Shay Reboh, Anaïs Dréau, and Jean-Michel Gérard demonstrating Purcell enhancement of silicon W color centers in circular Bragg grating cavities. https://lnkd.in/e9jWqrDY Generating on-demand single photons in silicon-on-insulator quantum photonic chips faces scalability challenges. W color centers, silicon tri-interstitial defects, show promise as artificial atoms. This paper describes quantum electrodynamics experiments with W centers in circular Bragg grating cavities, designed for moderate Purcell enhancement (Fp = 12.5) and efficient luminescence extraction (40%). Tuning the cavity to the zero-phonon transition of W centers at 1218 nm yields a 20-fold intensity boost and a 2-fold reduction in relaxation time. Finite-difference time-domain simulations align with a quantum efficiency of 65±10%. Therefore, W centers offer potential for the development of on-demand single-photon sources via cavity quantum electrodynamics in silicon photonic chips. This work is the result of a collaboration between PHELIQS - Quantum Photonics, Electronics and Engineering, University of Montpellier - Centre national de la recherche scientifique, and CEA-Leti #researchpaper #quantumphotonics #siliconphotonics #quantumtechnologies #photonics #nanotechnology CEA-Irig, Université Grenoble Alpes, Grenoble INP - UGA NPSC - Nanophysics and Semiconductors

Read the new paper by Josias Langbehn, Kyrylo Snizhko, Igor Gornyi, Giovanna Morigi, Yuval Gefen, and Christiane Koch studying dilute measurement-induced cooling of quantum systems to many-body ground states 👉 https://lnkd.in/euRkSkMb Cooling a quantum system to its ground state is important for the characterization of nontrivial interacting systems and in the context of a variety of quantum information platforms. In this paper, we identify conditions under which measurement-based cooling protocols can be taken to the ultimate dilute limit where the number of detectors is independent of system size. For two examples of frustration-free one-dimensional spin chains, we show that steering on a single link is sufficient to cool these systems into their unique ground states. We corroborate our analytical arguments with finite-size numerical simulations and discuss further applications of dilute cooling. This work is the result of a collaboration involving Freie Universität Berlin, PHELIQS - Quantum Photonics, Electronics and Engineering, Karlsruhe Institute of Technology (KIT), Universität des Saarlandes, and Weizmann Institute of Science. #researchpaper #quantum #theory CEA-Irig, 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

📝 New preprints from our team at Laboratoire Lumin (Lumière, Matière et Interfaces)! New insights into nanoscale mechanical measurement: 🔥 Our team has uncovered a surprising phenomenon: quantum fluctuations may significantly contribute to heating during the measurement of tiny objects, to temperatures far in excess of their fusion point! 🔬 This finding challenges existing theories and could have important implications for optomechanics and nanomechanics, and in particular in developing a new generation of ultra-sensitive nano-sensors. Warm thanks to all coworkers from École normale supérieure de Lyon, Institut Néel CNRS, PHELIQS - Quantum Photonics, Electronics and Engineering and University of Nottingham Learn more about our research: Theory: https://lnkd.in/g42XU5CQ Experiment: https://lnkd.in/guviMcHZ #nanotechnology #optomechanics #quantummechanics More detailed post in comment 👇

Read the new paper by Jesus Cañas, nevine rochat, Adeline Grenier, Audrey JANNAUD, Zineb Saghi, jean-luc Rouviere, Edith Bellet-Amalric, Anjali Harikumar, catherine Bougerol, Lorenzo Rigutti, and Eva Monroy analyzing the origing of bimodal emission in AlGaN quantum dots emitting in the ultraviolet spectral range. 👉 https://lnkd.in/e-XuQQTS Over the past five years, the field of solid-state UV lamps for disinfection has advanced significantly, focusing on wavelengths around 270 nm and 230 nm. A key player in this domain is the AlGaN LED technology, in spite of their relatively low power efficiency. An exciting alternative is electron beam-pumped lamps using AlGaN/AlN quantum dots (QDs). However, extending this technology to the far UV-C range has its challenges, notably the emergence of bimodal emission patterns, which could undermine disinfection effectiveness. This paper unveils the origin of bimodal emission in AlGaN/AlN QDs superlattices exhibiting high internal quantum efficiency in the 230-300 nm range. The bimodality is linked to cone-shaped extended defects stemming from the interface between the AlN buffer layer and the QD superlattice. These defects, characterized by dislocation with a strong shear strain field, facilitate an environment where Ga enrichment occurs due to the Ehrlich-Schwoebel effect, leading to variation in QD size and chemistry. This work is a collaboration between the NPSC - Nanophysics and Semiconductors team of PHELIQS - Quantum Photonics, Electronics and Engineering and Institut Néel CNRS, CEA-Leti, the Modeling and Exploration of Materials laboratory (MEM) of CEA-Irig, and Universit�� de Rouen. #researchpaper #quantumdots #epitaxy #aluminiumnitride #galliumnitride #ultraviolet NPSC - Nanophysics and Semiconductors CEA-Irig, Université Grenoble Alpes, Grenoble INP - UGA

📣We are thrilled to share our latest scientific results on demonstrating the coherent on-demand generation of indistinguishable photons in the telecom C-band using single QD devices, published in ACS Photonics. Link in the comment field👇 NanoPhoton - Center for Nanophotonics members Paweł Holewa, Kresten Yvind, and Elizaveta Semenova, in collaboration with TU Berlin (Tobias Heindel, Daniel Vajner, Martin von Helverse ), Politechnika Wrocławska (Marcin Syperek, Anna Musiał, Emilia Zięba-Ostój, Maja Wasiluk), DTU Physics (@Alexander Huck) and DTU Electro (Aurimas Sakanas, Niels Gregersen) explore the fascinating world of semiconductor quantum dots (QDs) and their pivotal role in advancing photonic quantum technologies. This research focuses on harnessing the power of InAs/InP epitaxially grown quantum dots as quantum light sources in the telecom C-band —an essential component for various applications in quantum communications compatible with integration via fibre-optical networks. Through the implementation of two-photon resonant excitation of the biexciton–exciton radiative cascade, high single-photon purity for both exciton and biexciton photons was shown. Notably, the state preparation fidelities for achieving population inversion of the solid-state three-level system at the π-pulse, resulting in values surpassing 80%🔆 #quantumdots #quantumlightsources #semiconductor DTU Electro DTU - Technical University of Denmark Danmarks Grundforskningsfond / The Danish National Research Foundation

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Read the new paper by Lucie Valera, Lucas Jaloustre, Valérie Reita, Saron R.S. De Mello, Edith Bellet-Amalric, Camille Petit-Etienne, Erwine Pargon, Gwénolé JACOPIN, and Christophe DURAND demonstrating organized AlN nanowire arrays by top-down processing and MOVPE overgrowth. 👉 https://lnkd.in/e_2mifnJ The paper demonstrates the fabrication of organized AlN nanowires with well-defiend m-plane sidewalls, showing narrow near-band-edge emission. The process combine first plasma etching and wet KOH etching process, to obtain strain-free AlN nanopillars with various densities and diameters as small as 250 nm. In a second step, overgrowth by MOVPE is performed to recover m-oriented hexagonal facets. A growth model is proposed to describe the evolution of the AlN lateral growth rate as a function of the spacing and diameter of the AlN nanopillars, identifying two main contributions: diffusion from the substrate and direct growth from the vapor phase. This work is a collaboration between the NPSC - Nanophysics and Semiconductors team of PHELIQS - Quantum Photonics, Electronics and Engineering, CEA-Leti, Institut Néel CNRS, and Laboratoire des Technologies de la Microélectronique - LTMLab. #researchpaper #nanowires #aluminiumnitride #ultraviolet CEA-Irig, Université Grenoble Alpes, Grenoble INP - UGA

📢 Exciting News! 📚 Our team has been busy with groundbreaking research, resulting in several publications that push the boundaries of photonics and quantum technology. Here's a glimpse of our latest achievements: 🔍 "Scalable and efficient grating couplers on low-index photonic platforms enabled by cryogenic deep silicon etching" - authored by Emma, Maik, Linus, Wolfram, and Francesco. This paper explores innovative techniques for enhancing grating couplers' efficiency on low-index photonic platforms, offering scalability and efficiency, even at cryogenic temperatures. https://lnkd.in/er6ZSM9w 🌟 "Layered Gallium Monosulfide as Phase-Change Material for Reconfigurable Nanophotonic Components On-Chip" - with contributions from our colleagues Anna, Frank, and Wolfram. This publication delves into the utilization of layered gallium monosulfide as a phase-change material, paving the way for reconfigurable nanophotonic components on-chip. https://lnkd.in/eUzSV2bQ 🌈 "Controlling All Degrees of Freedom of the Optical Coupling in Hybrid Quantum Photonics" - featuring contributions from Anna, Helge, Daniel, and Wolfram. This paper explores advanced methods to control the optical coupling in hybrid quantum photonics, offering insights into the manipulation of quantum systems with unprecedented precision. https://lnkd.in/eU5j2CPs #Photonics #QuantumTechnology #Research #Innovation

Read the new paper by Régis Mélin, Clemens Winkelmann, and Romain Danneau on magnetointerferometry of multiterminal Josephson junctions https://lnkd.in/e_tDbANu Recently, there has been growing interest in superconducting multiterminal systems, as they exhibit unique and complex behaviors. Early theoretical research hinted at their unconventional characteristics, and subsequent studies have uncovered a range of fascinating phenomena in these intricate Josephson junctions. These include the inter-Cooper pair correlations known as quartets, the presence of Weyl point singularities, intricate topological features in the Andreev bound state spectrum, and energy level repulsion within Andreev molecules. In this context, we introduce a microscopic model that enables the calculation of how the critical current varies with the magnetic field across different setups. Our approach uses a broad-gap Hamiltonian where the supercurrent initiation is linked to the trace of the phase in the vector potential. Thus, we delineate the critical current's magnetic field dependency. Although our model reaffirms the conventional interferometric patterns observed in two-terminal systems, it also reveals that introducing an additional lead significantly alters the critical current's response to magnetic fields. In systems with four terminals, our results indicate that the supercurrent extends across all superconducting leads, suggesting a phenomenon akin to ergodicity. This work is a colaboration between Institut Néel CNRS, PHELIQS - Quantum Photonics, Electronics and Engineering, and Karlsruhe Institute of Technology (KIT). #quantum #theoreticalphysics #magnetism #JosephsonJunction CEA-Irig, Université Grenoble Alpes, Grenoble INP - UGA