Article
Physics, Applied
Martin Nurizzo, Baptiste Jadot, Pierre-Andre Mortemousque, Vivien Thiney, Emmanuel Chanrion, Matthieu Dartiailh, Arne Ludwig, Andreas D. Wieck, Christopher Bauerle, Matias Urdampilleta, Tristan Meunier
Summary: Recent demonstrations using electron spins stored in quantum dot array as qubits show promise for developing a scalable quantum computing platform. By partitioning the system with inter-dot tunnel barriers, the precise control of the quantum dot parameters can be simplified and protection against unwanted charge displacement can be achieved.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Mahdi Asgari, Dominique Coquillat, Guido Menichetti, Valentina Zannier, Nina Diakonova, Wojciech Knap, Lucia Sorba, Leonardo Viti, Miriam Serena Vitiello
Summary: Low-dimensional nanosystems show promise in manipulating and controlling photons with large sensitivities, and by quantum engineering tailored energy levels of localized electrons can result in efficient quantum sensors. Utilizing few-electron physics, millimeter-wave nanodetectors have been developed to efficiently sense radiation at 0.6 THz with low noise levels, opening up prospects for quantum communications and cryptography.
Article
Chemistry, Multidisciplinary
Marissa S. Martinez, Michelle A. Nolen, Nicholas F. Pompetti, Lee J. Richter, Carrie A. Farberow, Justin C. Johnson, Matthew C. Beard
Summary: Controlling the binding of functional organic molecules on quantum dot surfaces is crucial for understanding the resulting organic-inorganic hybrid behavior. In this study, the binding of tetracenedicarboxylate ligands on PbS quantum dots was varied through solid-state ligand exchange. Different ligand concentrations led to different structures and properties, with low concentrations resulting in mixed ligand structures, intermediate concentrations resulting in ligand-ligand interactions through hydrogen bonding, and high concentrations resulting in complete ligand exchange.
Article
Chemistry, Physical
Bin Bin Jin, Shu Ying Kong, Guo Qing Zhang, Xing Qiao Chen, Hong Shan Ni, Fan Zhang, Dan Jun Wang, Jing Hui Zeng
Summary: The study focuses on inhibiting interfacial charge recombination in CdSe QDSSCs by constructing a ZnS/QDs/ZnS double-layer barrier structure and applying an electric field in VASILAR, achieving higher efficiency.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Yang-Yang Ju, Xiao-Xiao Shi, Shu-Yu Xu, Xiao-Hui Ma, Rong-Jing Wei, Hao Hou, Cheng-Chao Chu, Di Sun, Gang Liu, Yuan-Zhi Tan
Summary: A water-soluble graphene quantum dot with deep-red emission and excellent sonodynamic sensitization has been synthesized. It can be dispersed in water without aggregation by decorating water-soluble functional groups. The deep-red emission allows for tracking its bio-process, showing good cell-uptake and long-term retention in tumor tissue. Compared to traditional sonosensitizers, it generates superior reactive oxygen species and exhibits excellent tumor inhibition potency. The biosafety of this graphene quantum dot has been validated in both in vitro and in vivo assays.
Article
Chemistry, Multidisciplinary
David B. Berkinsky, Andrew H. Proppe, Hendrik Utzat, Chantalle J. Krajewska, Weiwei Sun, Tara Sverko, Jason J. Yoo, Heejae Chung, Yu-Ho Won, Eunjoo Jang, Moungi G. Bawendi
Summary: Red-emitting InP/ZnSe/ZnS quantum dots (QDs) have narrower line widths than typically synthesized CdSe QDs, making them suitable for high color purity displays. Our analysis reveals that at low temperatures, phonon scattering and fine-structure splitting are the main broadening mechanisms, while at elevated temperatures, phonon scattering dominates and optical scattering plays a minor role in line broadening. These findings can inform the rational design of QD materials with narrower line widths.
Article
Physics, Applied
F. K. Unseld, M. Meyer, M. T. Madzik, F. Borsoi, S. L. de Snoo, S. V. Amitonov, A. Sammak, G. Scappucci, M. Veldhorst, L. M. K. Vandersypen
Summary: Semiconductor spin qubits have attracted attention as a potential platform for fault-tolerant quantum computing. In this study, researchers successfully created a tunnel-coupled 2x2 quantum dot array in a Si-28/SiGe heterostructure using high-quality materials and carefully designed gate patterns. By loading a single electron into each of the four quantum dots, the researchers were able to achieve the specific charge state (1,1,1,1). This work provides valuable information for the design of 2D quantum dot arrays and represents a significant step towards the operation of spin qubits in Si-28/SiGe quantum dots in two dimensions.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Margherita Biondi, Min-Jae Choi, Zhibo Wang, Mingyang Wei, Seungjin Lee, Hitarth Choubisa, Laxmi Kishore Sagar, Bin Sun, Se-Woong Baek, Bin Chen, Petar Todorovic, Amin Morteza Najarian, Armin Sedighian Rasouli, Dae-Hyun Nam, Maral Vafaie, Yuguang C. Li, Koen Bertens, Sjoerd Hoogland, Oleksandr Voznyy, F. Pelayo Garcia de Arquer, Edward H. Sargent
Summary: This study introduces a new method to improve facet alignment in CQD solids by adjusting the surface of CQDs, leading to enhanced coupling and improved performance of optoelectronic devices. This approach results in a 10x increase in hole mobility compared to control CQD solids, and enables photodiodes with 70% external quantum efficiency and rapid response times.
ADVANCED MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Sisi Liu, Chongjian Zhang, Shuangyuan Li, Yong Xia, Kang Wang, Kao Xiong, Haodong Tang, Linyuan Lian, Xinxing Liu, Ming-Yu Li, Manlin Tan, Liang Gao, Guangda Niu, Huan Liu, Haisheng Song, Daoli Zhang, Jianbo Gao, Xinzheng Lan, Kai Wang, Xiao Wei Sun, Ye Yang, Jiang Tang, Jianbing Zhang
Summary: By epitaxially coating a thin PbS shell over the PbSe QDs and in situ halide passivation, a strategy to decouple the restrictive relation between V-OC and J(SC) in QD IR photovoltaics is developed. This approach allows for excellent trap-state control and outstanding performance under filtered solar illumination, providing a new route to overcome the trade-off between V-OC and J(SC) limited by the photoactive layer with a given bandgap.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Spectroscopy
Yu-Ching Lin, Pei-Ying Lin, Shu-Ling Hsieh, Chen-Yu Tsai, Anil Kumar Patel, Reeta Rani Singhania, Rajendranath Kirankumar, Cheng-Di Dong, Chiu-Wen Chen, Shuchen Hsieh
Summary: This article describes an efficient and rapid detection method of formaldehyde by synthesizing APTES quantum dots, which react with formaldehyde to generate fluorescence quenching for detection.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2022)
Article
Chemistry, Multidisciplinary
Hyeongwoo Lee, Ju Young Woo, Dae Young Park, Inho Jo, Jusun Park, Yeunhee Lee, Yeonjeong Koo, Jinseong Choi, Hyojung Kim, Yong-Hyun Kim, Mun Seok Jeong, Sohee Jeong, Kyoung-Duck Park
Summary: Strain engineering of perovskite quantum dots (pQDs) at the single-emitter level has been achieved using tip-enhanced photoluminescence (TEPL) spectroscopy. By systematically modulating tip-induced compressive strain, dynamic bandgap engineering in a reversible manner has been successfully demonstrated on a single pQD.
Article
Nanoscience & Nanotechnology
Pierre-Andre Mortemousque, Emmanuel Chanrion, Baptiste Jadot, Hanno Flentje, Arne Ludwig, Andreas D. Wieck, Matias Urdampilleta, Christopher Bauerle, Tristan Meunier
Summary: Controlling individual quantum objects organized in arrays is essential for scalable quantum information platforms. By integrating nearest-neighbour coupled semiconductor quantum dots in a 3 x 3 array with finely tuned virtual gate control, 2D coherent spin control has been achieved. Recent efforts in controlling electron spins in quantum dot arrays have led to the realization of quantum simulators and multielectron spin-coherent manipulations. However, demonstrating 2D scaling with a high connectivity of such implementations remains a challenge.
NATURE NANOTECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Carlo Nazareno Dibenedetto, Elisabetta Fanizza, Liberato De Caro, Rosaria Brescia, Annamaria Panniello, Raffaele Tommasi, Chiara Ingrosso, Cinzia Giannini, Angela Agostiano, Maria Lucia Curri, Marinella Striccoli
Summary: The study investigates the interaction mechanisms between QDs by forming small heteroassemblies composed of several different-sized CdSe QDs in solution, tuning the interparticle distance by varying the length of the alkyl chain. The research provides a thorough spectroscopic investigation to rationalize the coupling mechanism between the interacting nanoparticles, ranging from charge transfer/wavefunction delocalization to energy transfer, based on their separation distance.
MATERIALS RESEARCH BULLETIN
(2022)
Article
Chemistry, Multidisciplinary
Hao Zhang, Parinaz Moazzezi, Juanjuan Ren, Brett Henderson, Cristina Cordoba, Vishal Yeddu, Arthur M. Blackburn, Makhsud Saidaminov, Irina Paci, Stephen Hughes, Reuven Gordon
Summary: Perovskite quantum dots (PQDs) show promise in various applications, including efficient solar cells, bright light emitting devices, and quantum sources of light. Researchers used double-nanohole optical trapping to size individual dots and observed the coupling between dots. The findings provide insights for in situ control of PQD growth and studies of their coupling with quantum information applications in mind.
Article
Physics, Applied
Qingshuang Zhi, Kongfa Chen, Zelong He
Summary: This study discusses the design of several four-quantum-dot topological structures and the impact of interdot coupling strength and intradot Coulomb interactions on conductance. The manipulation of the location of the anti-resonance band by tuning the interdot coupling strength suggests a potential physical scheme for an effective quantum switch. The Fano anti-resonance peak may evolve into a resonance peak, and for a specific value of the interdot coupling strength, two Fano anti-resonances collapse to form bound states in the continuum. Additionally, the number of anti-resonance bands increases due to many-body effects, providing a theoretical basis for the design of quantum computing devices.
MODERN PHYSICS LETTERS B
(2021)
Article
Chemistry, Multidisciplinary
Yujing Ma, Kazuma Sugawara, Yusuke Ishigaki, Kewei Sun, Takanori Suzuki, Shigeki Kawai
Summary: We successfully synthesized pyrrolopyrrole-bridged ladder oligomers from 11,11,12,12-tetrabromo-1,4,5,8-tetraaza-9,10-anthraquinodimethane molecules on Ag(111) using bond-resolved scanning tunneling microscopy. The non-dehydrogenative cyclization between pyrazine and ethynylene/cumulene groups has a low-activation barrier, forming dimeric oligomers containing dipyrazinopyrrolopyrrolopyrazine units and providing new insights into strain sensitivity in ladder-oligomer formation.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Hanaa. M. Ahmed, Zakaria M. Abd El-Fattah, Noori. S. Anad, Mohamed Attallah, Hany. H. El-Bahnasawy
Summary: In this study, pure polyvinyl chloride (PVC) and PVC-based nanocomposites containing pure and Cr-doped ZnO nanoparticles were fabricated using the solvent casting method. Scanning electron microscopy images confirmed the successful incorporation of nanoparticles within the PVC matrix. The nanocomposite samples exhibited improved thermo-mechanical stability and remarkable enhancement in dielectric response.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Article
Chemistry, Multidisciplinary
Kewei Sun, Orlando J. Silveira, Yujing Ma, Yuri Hasegawa, Michio Matsumoto, Satoshi Kera, Ondrej Krejci, Adam S. Foster, Shigeki Kawai
Summary: Substituting carbon with silicon in organic molecules and materials is a challenging task, but in this study, the researchers successfully synthesized one- and two-dimensional covalent organic frameworks with atomically precise Si substitution. The structures were characterized using high-resolution scanning tunnelling microscopy and photoelectron spectroscopy, and it was found that each Si atom in a hexagonal C4Si2 ring was covalently linked to one terminal Br atom.
Article
Chemistry, Multidisciplinary
Joel Deyerling, Ignacio Piquero-Zulaica, Mustafa A. Ashoush, Knud Seufert, Mohammad A. Kher-Elden, Zakaria M. Abd El-Fattah, Willi Auwaerter
Summary: Engineering quantum phenomena of two-dimensional nearly free electron states has been a prominent topic in nanoscience. However, current strategies for confining nanostructures do not provide protection against external influences, limiting their potential applications. This article presents a scalable growth approach using h-BN overlayer to form nanoporous CuS networks, effectively confining electronic states and forming an array of quantum dots. The protective properties of the h-BN capping are also tested, representing a significant step towards robust surface state-based electronic devices.
Article
Chemistry, Multidisciplinary
Xiushang Xu, Kewei Sun, Atsushi Ishikawa, Akimitsu Narita, Shigeki Kawai
Summary: Graphene nanoribbons and nanographenes synthesized on surfaces have great potential for studying magnetism in nano-spintronics. In this study, unprecedented 7-armchair GNRs with p-extended structures were synthesized and shown to exhibit Kondo resonances even on bare Au(111). The unique nonplanar termini formed by rearrangement reactions reduce the interaction with the Au(111) surface, allowing for spin localization and control of magnetism on metal substrates.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Zhao Liu, J. G. Vilhena, Ernst Meyer, Antoine Hinaut, Sebastian Scherb, Feng Luo, Junyan Zhang, Thilo Glatzel, Enrico Gnecco
Summary: Friction control and technological advancement are closely linked, and two-dimensional materials have unique characteristics for achieving quasi-frictionless contacts. Inspired by twistronics, we propose to use moire patterning to control superlubricity. Experimental and simulation results reveal a transition from superlubric to dissipative sliding regime in graphene moires on a Pt(111) surface at different twist angles, triggered by the normal force. This transition is caused by a novel mechanism at the superlattice level, where the moire tiles are manipulated in a highly dissipative shear process associated with the twist angle. The atomic-level details of this dissipation allow the bridging of different sliding regimes in a reversible manner, providing a subtle intrinsic control of superlubricity.
Article
Multidisciplinary Sciences
Krisztina Regos, Remy Pawlak, Xing Wang, Ernst Meyer, Silvio Decurtins, Gabor Domokos, Kostya S. Novoselov, Shi-Xia Liu, Ulrich Aschauer
Summary: Molecular self-assembly plays a crucial role in technology and biological systems. Predicting pattern formation in 2D molecular networks is challenging, but this study introduces a simplified hierarchical geometric model based on graph theory to predict extended network patterns. The model provides pattern classification and prediction within specific ranges, offering a different perspective on self-assembled molecular patterns and potential applications.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Chemistry, Multidisciplinary
Takahiro Kojima, Karan Patel, Shunpei Nobusue, Ahmed Mahmoud, Cong Xie, Takahiro Nakae, Shigeki Kawai, Kazuhiro Fukami, Hiroshi Sakaguchi
Summary: The introduction of functional groups into polymers in an asymmetric manner has great potential for creating novel electronic and magnetic properties. By utilizing low halogen-contaminated metal surfaces, a vectorial on-surface synthetic technique was developed, which allows isotactic polymerization of compass precursors without the need for chiral catalysts. The resulting isotactic polymers exhibit polar 2D crystalline structures and offer new insights into stereoregular control and crystal engineering.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Ali A. Afify, Zakaria M. Abd El-Fattah, Mohamed Saleh M. Esmail, Hany H. El-Bahnasawy
Summary: This study investigates the structural and electronic properties of two different phases (cubic and tetragonal) of γ-Fe2O3 using density functional theory (DFT). The results are confirmed by experimental techniques such as X-ray diffraction, UV-visible spectroscopy, and Mössbauer spectroscopy. The study demonstrates the effectiveness of DFT methods in predicting and explaining the properties of magnetic materials and iron oxides.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Vahagn Mkhitaryan, Andrew P. Weber, Saad Abdullah, Laura Fernandez, Zakaria M. Abd El-Fattah, Ignacio Piquero-Zulaica, Hitesh Agarwal, Kevin Garcia Diez, Frederik Schiller, J. Enrique Ortega, F. Javier Garcia de Abajo
Summary: This study demonstrates the ability to confine light to atomic scales using atomically thin crystalline silver nanostructures. The fabricated structures allow for unprecedented control over optical field confinement in the near-infrared spectral region, leading to extreme spatial confinement and high-quality plasmon modes.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yiming Song, Ernst Meyer
Summary: In this Perspective, the recent advances in atomic friction of two-dimensional materials measured by friction force microscopy are presented. The main factors contributing to sliding friction between single asperity and a two-dimensional sheet are discussed, including material chemical identity, thickness, external load, sliding direction, velocity/temperature, and contact size. The latest progress of the more complex friction behavior of moire systems involving 2D layered materials is particularly focused on. The underlying mechanisms of these observed frictional characteristics during the sliding process are discussed through theoretical and computational studies, and a discussion and outlook on the perspective of this field are provided.
Article
Chemistry, Physical
Taehyun Won, Shohei Kumagai, Naotaka Kasuya, Yu Yamashita, Shun Watanabe, Toshihiro Okamoto, Jun Takeya
Summary: The chemical structures and morphologies of organic semiconductors (OSCs) and gate dielectrics were studied to improve the electrical performances of organic thin-film transistors (OTFTs). The charge transport properties at individual interfaces between the OSC surface and different gate dielectrics were investigated using solid and ionic gel gate dielectrics on the lower and upper surfaces of OSCs. The dual-gate transistor operation with solid/ionic gel gate exhibited improved hole mobility, attributed to the electric double layer formed at the ionic gel/uniform crystal surface.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Ryoto Yura, Shohei Kumagai, Kiyohiro Adachi, Daisuke Hashizume, Toshihiro Okamoto, Yoshiyuki Nonoguchi
Summary: This study demonstrates that supramolecular salt-functionalized n-doped ladder-type conducting polymers exhibit excellent stability in the presence of dry air.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Kewei Sun, Kazuma Sugawara, Andrey Lyalin, Yusuke Ishigaki, Kohei Uosaki, Oscar Custance, Tetsuya Taketsugu, Takanori Suzuki, Shigeki Kawai
Summary: In this study, complex organometallic oligomers were systematically synthesized on Cu(111) through sequential ring opening and bonding of phenanthroline derivatives by multiple Cu atoms. Characterization using scanning tunneling microscopy and density functional theory calculations revealed the role of Cu adatoms in the chiral oligomers. Furthermore, the strength of the bonds against sliding friction was found to be sufficient.
Article
Materials Science, Multidisciplinary
Ahmed M. Othman, Mohammad A. Kher-Elden, Ignacio Piquero-Zulaica, Johannes V. Barth, Moukhtar A. Hassan, Mohammed Farouk, Zakaria M. Abd El-Fattah
Summary: Quantum corrals, engineered through manipulation of individual adsorbed species, have contributed significantly towards understanding quantum phenomena. In this study, the nature of adatom scattering potentials is investigated using electron plane-wave expansion and boundary element methods. It is found that the experimentally observed modulation in local density of states (LDOS) can be reproduced regardless of the sign of the adatom potential. By arranging the adatoms into superlattices, it is possible to unambiguously identify the sign of the scattering potential. These findings have important implications for the development of quantum designer artificial superlattices.