Article
Multidisciplinary Sciences
Huan Zhao, Michael T. Pettes, Yu Zheng, Han Htoon
Summary: Researchers have successfully created telecom quantum emitters emitting in the telecommunication wavelength range by coupling 2D molybdenum ditelluride (MoTe2) to strain inducing nano-pillar arrays. The experiments show clear photon antibunching with 90% single-photon purity at 77K, and also reveal additional phenomena such as valley Zeeman splitting and restoring of valley symmetry in cross-polarized doublets under a magnetic field of 8T.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Emanuele Marino, Oleg A. Vasilyev, Bas B. Kluft, Milo J. B. Stroink, Svyatoslav Kondrat, Peter Schall
Summary: Nanocrystal assembly is crucial in developing next-generation optoelectronic devices. By utilizing critical Casimir attraction and electrostatic repulsion, the deposition process can be biased towards forming 2D layers or 3D islands, enabling control over the morphology of the deposited superstructure from crystalline to amorphous. This demonstrates the potential of critical Casimir interaction in directing the growth of future artificial solids based on nanocrystals.
NANOSCALE HORIZONS
(2021)
Article
Nanoscience & Nanotechnology
Jesus Canas, Anjali Harikumar, Stephen T. Purcell, Nevine Rochat, Adeline Grenier, Audrey Jannaud, Edith Bellet-Amalric, Fabrice Donatini, Eva Monroy
Summary: This article discusses the extension of AlxGa1-xN/AlN quantum dot technology for solid-state UV-C sources. It explores the impact of increasing the Al content in the quantum dots and reducing their growth time on the structural and optical properties. The study finds that while the internal quantum efficiency remains around 50% regardless of the Al content or emission wavelength, quantum dots emitting below 270 nm display bimodal luminescence due to fluctuations in their shape.
Article
Chemistry, Analytical
Dongquan Leng, Jihao Zhao, Xiang Ren, Rui Xu, Lei Liu, Xuejing Liu, Yuyang Li, Qin Wei
Summary: In this study, a split-type immunoassay strategy initiated by cation exchange and altering the capacity of an electron donor was optimized, using MoSe2/CdSe as a photoelectrode substrate and silver ions as the initiator of CE. The combination of ascorbate oxidase with MSNs improved the sensor's sensitivity and reliability, resulting in a broad linear range and low detection limit when applied to neuron-specific enolase.
ANALYTICAL CHEMISTRY
(2021)
Article
Nanoscience & Nanotechnology
Angus Gale, Chi Li, Yongliang Chen, Kenji Watanabe, Takashi Taniguchi, Igor Aharonovich, Milos Toth
Summary: This study presents a robust electron beam technique for site-specific fabrication of blue quantum emitters with a zero-phonon line at 436 nm. The emission intensity was found to be proportional to electron dose, and the efficacy of the fabrication method correlated with a defect emission at 305 nm.
Article
Chemistry, Physical
Junkai Ren, Luca Malfatti, Luigi Stagi, Davide Carboni, Roberto Anedda, Laura Calvillo, Plinio Innocenzi
Summary: Metal-free sulfur nanodots are a type of emerging nanoparticles used in photonics and nanobiotechnology. By modulating the surface interface with an organic polymer, the emission properties and colors of sulfur nanodots can be controlled.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Yi Ji, Quan Zuo, Chuanshuang Chen, Yannan Liu, Yiyong Mai, Yongfeng Zhou
Summary: In this study, a multi-to-one supramolecular photocatalyst was developed by assembling multiple graphene quantum dot antennas onto a single-Pt-site porphyrin unimolecular micelle catalytic center. This photocatalyst showed high efficiency in catalyzing water splitting into hydrogen using visible light.
CHEMICAL COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Eamonn T. Hughes, Gunnar Kusch, Jennifer Selvidge, Bastien Bonef, Justin Norman, Chen Shang, John E. Bowers, Rachel A. Oliver, Kunal Mukherjee
Summary: This study explores the impact of dislocations on carrier lifetimes, growth morphology, and luminescence in InAs quantum dots (QD) grown on silicon. The results show that dislocations significantly reduce carrier lifetimes, even in the presence of three-dimensional confinement. Additionally, misfit dislocations in the defect filter layers can induce crosshatch-like variations in QD emission color and intensity. This research provides valuable insights into the development of light sources for scalable silicon photonic integrated circuits.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Physics, Applied
Iman Ranjbar Jahromi, Gediminas Juska, Simone Varo, Francesco Basso Basset, Francesco Salusti, Rinaldo Trotta, Agnieszka Gocalinska, Francesco Mattana, Emanuele Pelucchi
Summary: GaAs quantum dots have emerged as advanced sources for polarization-entangled photon pairs, with this study focusing on epitaxially grown GaAs/AlxGa1-xAs site-controlled pyramidal QDs and their exceptional excitonic uniformity. The research also highlights the importance of biexciton binding energy and optical signature analysis for polarization entangled photon emission, as well as strategies to mitigate fine-structure splitting (FSS) non-uniformities.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Yanjie Huang, Dong Liu, Ruirui Guo, Bin Wang, Zhengzuo Liu, Yijia Guo, Jian Dong, Yuan Lu
Summary: This study developed a multifunctional magnetic nanozyme antibacterial strategy, utilizing magnetic control technology and highly toxic radicals to disrupt bacterial biofilms, with potential for combating drug-resistant bacterial infections.
Article
Materials Science, Multidisciplinary
Kristina M. Holsgrove, Tamsin O'Reilly, Simone Varo, Agnieszka Gocalinska, Gediminas Juska, Demie M. Kepaptsoglou, Emanuele Pelucchi, Miryam Arredondo
Summary: In this study, we used transmission electron microscopy techniques to investigate InGaAs/GaAs pyramidal quantum dots. Our findings revealed their 3-dimensional nature and their interconnection with other nanostructures. We also discovered that the shape of the dot is hexagonal rather than triangular, and observed the chemical distribution characteristics. These findings are of great significance for the further development of this type of quantum emitters.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Physics, Applied
H. Schuermann, G. Schmidt, F. Bertram, C. Berger, S. Metzner, P. Veit, A. Dadgar, A. Strittmatter, J. Christen
Summary: We report on the formation process of GaN/AlN quantum dots (QDs) and investigate the influence of the growth interruption time on their structural and optical properties. The results show that QDs develop from bulky GaN islands, which are influenced by threading dislocations and island morphology. The duration of growth interruption can be used to tune the emission wavelength of the QDs.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
Jing-Yang Chung, Zhang Li, Sarah A. Goodman, Jinkyu So, Govindo J. Syaranamual, Tara P. Mishra, Eugene A. Fitzgerald, Michel Bosman, Kenneth Lee, Stephen J. Pennycook, Silvija Gradecak
Summary: A new direct metal-organic chemical vapor deposition approach is demonstrated to grow In-rich InGaN quantum dots on Si substrates, leading to efficient long wavelength luminescence for white light emitting devices. The highly textured surface with V-pits allows localized high intensity red-shifted emission, opening up new pathways for solid-state white light emitting devices.
Article
Chemistry, Multidisciplinary
Stefan Feddersen, Viktoryia Zolatanosha, Ahmed Alshaikh, Dirk Reuter, Christian Heyn
Summary: Site-controlled Ga droplets on AlGaAs substrates are fabricated using area-selective deposition of Ga through apertures in a mask during molecular beam epitaxy (MBE). The Ga droplets can be crystallized into GaAs quantum dots using a crystallization step under As flux. A multiscale kinetic Monte Carlo (mkMC) simulation is used to model the complex process of self-assembled Ga droplet formation on AlGaAs for area-selective deposition. The simulation shows quantitative agreement with experimental results, but the model parameters differ from those of self-assembled droplet growth, which can be attributed to the presence of the mask in close proximity to the surface.
Article
Physics, Multidisciplinary
Andrea Secchi, Filippo Troiani
Summary: Few-electron states confined in quantum-dot arrays are crucial for quantum computing. The discrimination of these states can be achieved through gate-reflectometry and the measurement of the quantum capacitance. This study focuses on a double quantum dot system controlled by three gates, and provides analytical solutions for the two-electron case. The results reveal the dependence of the quantum capacitance matrix on the applied gate voltages, and demonstrate the potential of exploiting interdot coherences in addition to charge displacements.
Article
Optics
Josephine Nauschuetz, Hedwig Knoetig, Robert Weih, Julian Scheuermann, Johannes Koeth, Sven Hoefling, Benedikt Schwarz
Summary: This article presents GaSb-based interband cascade lasers (ICLs) operating at a center wavelength of 6.12 μm in continuous-wave mode up to a maximum temperature of 40 °C. The performance of the devices is improved by adjusting the Ga1-xInxSb layer thickness in the active region to reduce valence intersubband absorption. The optimization of the device design and electron injector rebalances the electron and hole concentrations, resulting in low threshold current densities and power consumption, making them suitable for mobile and compact sensing systems.
LASER & PHOTONICS REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Jonathan Jurkat, Sebastian Klembt, Marco De Gregorio, Moritz Meinecke, Quirin Buchinger, Tristan H. Harder, Johannes Beierlein, Oleg A. Egorov, Monika Emmerling, Constantin Krause, Christian Schneider, Tobias Huber-Loyola, Sven Hoefling
Summary: The introduction of topological physics to photonics has resulted in the development of robust photonic devices. While classical topological protection of light has been achieved, the utilization of quantum light sources in devices with topologically nontrivial resonances remains largely unexplored.
Article
Optics
Moritz Pfluger, Daniel Brunner, Tobias Heuser, James A. Lott, Stephan Reitzenstein, Ingo Fischer
Summary: In this article, we demonstrate the construction of the largest network of optically coupled semiconductor lasers reported so far by using diffractive optics in an external cavity to couple vertical-cavity surface-emitting lasers (VCSELs). We successfully align and lock 22 out of 25 lasers to an external drive laser, and show significant interaction between the lasers of the array. Our VCSEL network, with its high homogeneity, strong interaction, and scalability, serves as a promising platform for experimental investigations of complex systems and has direct applications as a photonic neural network.
Article
Engineering, Electrical & Electronic
Nikolai B. Chichkov, Amit Yadav, Franck Joulain, Solenn Cozic, Semyon V. Smirnov, Leon Shterengas, Julian Scheuermann, Robert Weih, Johannes Koeth, Sven Hofling, Ulf Hinze, Samuel Poulain, Edik U. Rafailov
Summary: Building upon recent advances in GaSb-based diode lasers and Er-doped fluoride fibre technologies, this article demonstrates the fibre-based amplification of mid infrared diode lasers around 2.78 μm for the first time. The experimental results show output powers up to 0.9 W, pulse durations as short as 20 ns, and pulse repetition rates up to 1 MHz. Additionally, the impact of different fibre end-cap materials on laser performance is analyzed.
IEEE PHOTONICS JOURNAL
(2023)
Article
Physics, Applied
Quirin Buchinger, Simon Betzold, Sven Hoefling, Tobias Huber-Loyola
Summary: We conducted an optical study on various device designs of electrically contactable circular Bragg grating cavities in labyrinth geometries. In order to establish an electrical connection between the central disk and the surrounding membrane, we introduced connections between the adjacent rings separated by air gaps. By rotating these connections to create a labyrinth-like structure, we improved mode confinement, far-field pattern, and Purcell factor compared to layouts with connections arranged in straight lines. Reflectivity measurements and simulations were conducted to investigate the effects of different arrangements and sizes of connections on the optical properties and to determine the optimal design.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Bing Liu, Tim Wagner, Stefan Enzner, Philipp Eck, Martin Kamp, Giorgio Sangiovanni, Ralph Claessen
Summary: By synthesizing ultrathin Sb films on semi-insulating InSb(111)A substrate, researchers observe a pronounced moire pattern on the Sb films and confirm experimentally that the topological surface state persists and shifts toward lower binding energies with a decrease in Sb thickness, in agreement with theoretical predictions.
Article
Chemistry, Multidisciplinary
Yago del Valle-Inclan Redondo, Christian Schneider, Sebastian Klembt, Sven Hoefling, Seigo Tarucha, Michael D. Fraser
Summary: We have created a rotating polariton condensate at gigahertz frequencies by off-resonantly pumping with a rotating optical stirrer composed of structured laser modes. The results show that the rotating polariton condensate acquires angular momentum exceeding the critical 1n/particle and demonstrates deterministic nucleation and capture of quantized vortices with a handedness controlled by the pump rotation direction. This study enables new opportunities for exploring open dissipative superfluidity, ordering of non-Hermitian quantized vortex matter, and topological states in a highly nonlinear, photonic platform.
Article
Physics, Multidisciplinary
Carolin Lueders, Matthias Pukrop, Franziska Barkhausen, Elena Rozas, Christian Schneider, Sven Hoefling, Jan Sperling, Stefan Schumacher, Marc Assmann
Summary: We have developed a novel phase-space method to dynamically monitor quantum coherence in polariton condensates. Our approach allows us to quantify complex decoherence mechanisms and provides a stable system for long-term coherence. By reconstructing phase-space functions from homodyne detection data, we have demonstrated the potential of using quantum coherence for information processing up to the nanosecond regime.
PHYSICAL REVIEW LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Daniel Wigger, Johannes Schall, Marielle Deconinck, Nikolai Bart, Pawel Mrowinski, Mateusz Krzykowski, Krzysztof Gawarecki, Martin von Helversen, Ronny Schmidt, Lucas Bremer, Frederik Bopp, Dirk Reuter, Andreas D. Wieck, Sven Rodt, Julien Renard, Gilles Nogues, Arne Ludwig, Pawel Machnikowski, Jonathan J. Finley, Stephan Reitzenstein, Jacek Kasprzak
Summary: Semiconductor quantum dot molecules are versatile in their tunability of optical properties and their ability to cover different energy scales associated with charge and spin physics, making them promising for quantum technological applications. This study demonstrates the coherent control of interdot tunnel-coupling in these systems, focusing on the quantum coherence of optically active trion transitions. By using ultrafast four-wave mixing spectroscopy, a quantum coherence is generated in one trion complex and transferred and probed in another trion configuration, with theoretical modeling providing an explanation of the underlying coupling mechanism and dynamic processes.
Article
Physics, Applied
Chirag Chandrakant Palekar, Manan Shah, Stephan Reitzenstein, Arash Rahimi-Iman
Summary: This study reports the design, nanofabrication, and characterization of high-quality polymer-based micromirror structures using the 3D two-photon polymerization lithography technique. The innovative concept provides microstructures for fast prototyping and offers cost-effective and environmentally sensitive polymer-based mirrors compatible with a wide range of wavelengths. The research demonstrates reproducible and mechanically stable 3D printed micromirrors that enable hybrid nanophotonic devices based on quantum dots, molecules, or 2D quantum materials.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Michael Seidel, Yuhui Yang, Thorsten Schumacher, Yongheng Huo, Saimon Filipe Covre da Silva, Sven Rodt, Armando Rastelli, Stephan Reitzenstein, Markus Lippitz
Summary: Reliable single-photon sources, high coupling efficiency, and low propagation losses are key requirements for quantum plasmonic nanocircuits. The best overall performance of these nanocircuits is achieved by adding a spacer layer between the quantum dot and the plasmonic waveguide, resulting in an improved coupling efficiency through standing wave interference.
Article
Optics
Zaijun Chen, Alexander Sludds, Ronald Davis III, Ian Christen, Liane Bernstein, Lamia Ateshian, Tobias Heuser, Niels Heermeier, James A. Lott, Stephan Reitzenstein, Ryan Hamerly, Dirk Englund
Summary: Researchers demonstrate an optical computing architecture using micrometre-scale VCSEL transmitter arrays, achieving an energy efficiency of 7 fJ per operation and a compute density of 6 tera-operations mm(-2) s(-1). This system overcomes the challenges of ONNs, such as high energy consumption, low compute density, and long latency, providing a new way to accelerate machine learning tasks.
Article
Physics, Multidisciplinary
Yanqiang Guo, Jianfei Zhang, Xiaomin Guo, Stephan Reitzenstein, Liantuan Xiao
Summary: The emission characteristics of quantum-dot micropillar lasers (QDMLs) lie at the intersection of nanophotonics and nonlinear dynamics, providing an ideal platform for studying the optical interface between classical and quantum systems. In this research, a noise-induced bimodal QDML with orthogonal dual-mode outputs is modeled, and the nonlinear dynamics, stochastic mode jumping, and quantum statistics are investigated. The results show that noise-induced effects lead to the emergence of two intensity bifurcation points for the strong and weak modes, and the maximum output power of the strong mode increases with the noise intensity. The anti-correlation of the two modes reaches its maximum at the second intensity bifurcation point. The dual-mode stochastic jumping frequency and effective bandwidth can exceed 100 GHz and 30 GHz under the noise-induced effect. Photon bunching (g((2))(0) > 1) of both modes is observed over a wide range of noise intensities and injection currents. The photon number distribution of the strong or weak mode becomes a mixture of Bose-Einstein and Poisson distributions, with the proportion of the Poisson distribution increasing in the high injection current region for the strong mode and decreasing for the weak mode.
NEW JOURNAL OF PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Maciej Jaworski, Aleksandra Chudzynska, Pawel Mrowinski, Joanna Prazmowska-Czajka, Wojciech Kijaszek, Jan Grosse, Sven Rodt, Stephan Reitzenstein, Grzegorz Sek
Summary: This study proposes the xenon-plasma FIB technology as an alternative solution for the fabrication of photonic microstructures. By optimizing the processing method, GaAs-based photonic microstructures with InGaAs QDs emitting bright light were successfully fabricated.
OPTICAL MATERIALS EXPRESS
(2023)
Article
Materials Science, Multidisciplinary
Martin von Helversen, Lara Greten, Imad Limame, Ching-Wen Shih, Paul Schlaugat, Carlos Anton-Solanas, Christian Schneider, Barbara Rosa, Andreas Knorr, Stephan Reitzenstein
Summary: This study explores the emission properties of quantum emitters in a WSe2 monolayer induced by metallic nanoparticles, and verifies their single-photon purity. The temperature-dependent coherence time and decay time are determined through Michelson interferometry and time-resolved photoluminescence experiments.
