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Two-dimensional MOF and COF nanosheets for next-generation optoelectronic applications

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Coordination Chemistry Reviews 2021年 435卷

作者： Xiaohui Ren Gengcheng Liao Zhongjun Li Hui Qiao Yuan Zhang Xiang Yu Bing Wang Hui Tan Li Shi Xiang Qi Han Zhang Hunan Key Laboratory of Micro-Nano Energy Materials and Devices and Laboratory for Quantum Engineering and Micro-Nano Energy Technology School of Physics and Optoelectronic Xiangtan University Xiangtan 411105 PR China Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology and Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province Shenzhen University Shenzhen 518060 PR China Department of Neurosurgery & Shenzhen Key Laboratory of Neurosurgery The First Affiliated Hospital of Shenzhen University/Shenzhen Second People’s Hospital Shenzhen University Shenzhen 518060 PR China International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education Institute of Microscale Optoelectronics Shenzhen University Shenzhen 518060 PR China School of Materials Science & Chemical Engineering Ningbo University Ningbo Zhejiang 315211 PR China

The development of optoelectronics technology greatly contributes to our daily life and industrial evolution. In particular, two-dimensional (2D) materials with ultrathin structure have received worldwide research interests in the field of optoelectronics mainly owing to the intrinsic electronic and optical attributes. The on-going researches indicate that electrically conducting MOF and COF demonstrate distinctive properties and promising surface functionality, while their inherent band structure and electronic features can be rationally controlled by structural modification. With rapid development of 2D materials-based optoelectronic devices, the utilization of 2D polymer MOF and COF semiconductors has become a new tendency to meet the scope of adaptive, low-cost, and flexible device fabrication. In this review, the recent research activities on 2D MOF and COF materials are provided. The fabrication and semiconducting properties of 2D MOF and COF materials have been explained. Apart from that, both advantages and limitations of the newly developed 2D MOF and COF materials regarding their potential in optoelectronic devices have been discussed. Additionally, different types of 2D MOF and COF materials and performance adjusting strategies have been systematically summarized. Furthermore, the remaining challenges and current prospects of applying 2D MOF and COF into optical-to-electrical and electrical-to-optical conversion devices have been introduced.

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Calibration of cryogenic amplification chains using normal-metal-insulator-superconductor junctions

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arXiv 2019年

作者： Hyyppä, E. Jenei, M. Masuda, S. Sevriuk, V. Tan, K.Y. Silveri, M. Goetz, J. Partanen, M. Lake, R.E. Grönberg, L. Möttönen, M. QCD Labs QTF Centre of Excellence Department of Applied Physics Aalto University P.O. Box 13500 AaltoFI-00076 Finland College of Liberal Arts and Sciences Tokyo Medical and Dental University Ichikawa272-0827 Japan Center for Quantum Computation and Communication Technology School of Electrical Engineering Telecommunications University of New South Wales SydneyNSW2052 Australia Research Unit of Nano and Molecular Systems University of Oulu P.O. Box 3000 OuluFI-90014 Finland VTT Technical Research Centre of Finland QFT Center of Excellence P.O. Box 1000 AaltoFI-02044 Finland

Various applications of quantum devices call for an accurate calibration of cryogenic amplification chains. To this end, we present a convenient calibration scheme and use it to accurately measure the total gain and noise temperature of an amplification chain by employing normal-metal-insulator-superconductor (NIS) junctions. Our method is based on the radiation emitted by inelastic electron tunneling across voltage-biased NIS junctions. We derive an analytical equation that relates the generated power to the applied bias voltage which is the only control parameter of the device. After the setup has been characterized using a standard voltage reflection measurement, the total gain and the noise temperature are extracted by fitting the analytical equation to the microwave power measured at the output of the amplification chain. The 1σ uncertainty of the total gain of 51.84 dB appears to be of the order of 0.1 dB. Copyright © 2019, The Authors. All rights reserved.

关键词： Metal insulator boundaries

Routing valley excitons in a monolayer mos2 with a metasurface

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arXiv 2018年

作者： Sun, Liuyang Wang, Chun-Yuan Krasnok, Alexandr Choi, Junho Shi, Jinwei Gomez-Diaz, Juan Sebastian Zepeda, Andre Gwo, Shangjr Shih, Chih-Kang Alù, Andrea Li, Xiaoqin Department of Physics Complex Quantum Systems Texas Materials Institutes University of Texas at Austin AustinTX78712 United States Department of Physics National Tsing-Hua University Hsinchu30013 Taiwan Department of Electrical and Computer Engineering University of Texas at Austin AustinTX78712 United States Department of Physics and Applied Optics Beijing Area Major Laboratory Beijing Normal University Beijing100875 China Department of Electrical and Computer Engineering University of California Davis DavisCA95616 United States National Synchrotron Radiation Research Center Hsinchu30076 Taiwan CUNY Advanced Science Research Center New YorkNY10031 United States

Excitons in monolayer transition metal dichalcogenides (TMDs) are formed at K and K' points at the boundary of the Brillouin zone. They acquire a valley degree of freedom, which may be used as a complementary platform for information transport and processing1-3. In a different context, metasurfaces consisting of engineered arrays of polarizable inclusions have enabled the manipulation of light in unprecedented ways, and found applications in imaging4-8, optical information processing9-11, and cloaking12-15. Here, we demonstrate that, by coupling a MoS2 monolayer to a suitably designed metasurface consisting of asymmetric grooves, valley polarized excitons can be sorted and spatially separated even at room temperature. Emission from valley excitons is also separated in K-space, i.e., photons with opposite helicity are emitted to different directions. Our work demonstrates that metasurfaces can facilitate valley transport and establish an interface between valleytronic and photonic devices, thus addressing outstanding challenges in the nascent field of valleytronics. Copyright © 2018, The Authors. All rights reserved.

关键词： Landforms

Dynamics of reverse annealing for the fully-connected p-spin model

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arXiv 2019年

作者： Yamashiro, Yu Ohkuwa, Masaki Nishimori, Hidetoshi Lidar, Daniel A. Department of Physics Tokyo Institute of Technology Nagatsuta-cho Midori-ku Yokohama226-8503 Japan Jij Inc. High tech Hongo Building 1F 5-25-18 Hongo Bunkyo Tokyo113-0033 Japan NTT DATA Mathematical Systems Inc. Shinanomachi Shinjuku-ku Tokyo160-0016 Japan Institute of Innovative Research Tokyo Institute of Technology Nagatsuta-cho Midori-ku Yokohama226-8503 Japan Graduate School of Information Sciences Tohoku University Sendai980-8579 Japan Departments of Electrical Engineering Chemistry and Physics & Astronomy University of Southern California Los AngelesCA90089 United States Center for Quantum Information Science & Technology University of Southern California Los AngelesCA90089 United States

Reverse annealing is a relatively new variant of quantum annealing, in which one starts from a classical state and increases and then decreases the amplitude of the transverse field, in the hope of finding a better classical state than the initial state for a given optimization problem. We numerically study the unitary quantum dynamics of reverse annealing for the mean-field-type p-spin model and show that the results are consistent with the predictions of equilibrium statistical mechanics. In particular, we corroborate the equilibrium analysis prediction that reverse annealing provides an exponential speedup over conventional quantum annealing in terms of solving the p-spin model. This lends support to the expectation that equilibrium analyses are effective at revealing essential aspects of the dynamics of quantum annealing. We also compare the results of quantum dynamics with the corresponding classical dynamics, to reveal their similarities and differences. We distinguish between two reverse annealing protocols we call adiabatic and iterated reverse annealing. We further show that iterated reverse annealing, as has been realized in the D-Wave device, is ineffective in the case of the p-spin model, but note that a recently-introduced protocol ("h-gain"), which implements adiabatic reverse annealing, may lead to improved performance. Copyright © 2019, The Authors. All rights reserved.

关键词： quantum theory

Device Architecture for Coupling Spin Qubits via an Intermediate quantum State

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Physical Review Applied 2018年第4期10卷 044058-044058页

作者： X.G. Croot S.J. Pauka J.D. Watson G.C. Gardner S. Fallahi M.J. Manfra D.J. Reilly ARC Centre of Excellence for Engineered Quantum Systems School of Physics The University of Sydney Sydney New South Wales 2006 Australia Department of Physics and Astronomy Purdue University West Lafayette Indiana 47907 USA Birck Nanotechnology Center Purdue University West Lafayette Indiana 47907 USA Station Q Purdue Purdue University West Lafayette Indiana 47907 USA School of Materials Engineering and School of Electrical and Computer Engineering Purdue University West Lafayette Indiana 47907 USA Microsoft Corporation Station Q Sydney The University of Sydney Sydney New South Wales 2006 Australia

We demonstrate a scalable device architecture that facilitates indirect exchange between singlet-triplet spin qubits, mediated by an intermediate quantum state. The device comprises five quantum dots, which can be independently loaded and unloaded via tunneling to adjacent reservoirs, avoiding charge latch-up common in linear dot arrays. In a step toward realizing two-qubit entanglement based on indirect exchange, the architecture permits precise control over tunnel rates between the singlet-triplet qubits and the intermediate state. We show that by our separating qubits by approximately 1 μm, the residual capacitive coupling between them is reduced to approximately 7 μeV.

关键词： Coulomb blockade quantum gates quantum information architectures & platforms quantum information with solid state qubits quantum state engineering III-V semiconductors quantum dots Spin

Cation distribution and magnetic properties in ultrathin (Ni1–xCox)Fe2O4(x=0–1) layers on Si(111) studied by soft x-ray magnetic circular dichroism

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Physical Review Materials 2018年第10期2卷 104416-104416页

作者： Yuki K. Wakabayashi Yosuke Nonaka Yukiharu Takeda Shoya Sakamoto Keisuke Ikeda Zhendong Chi Goro Shibata Arata Tanaka Yuji Saitoh Hiroshi Yamagami Masaaki Tanaka Atsushi Fujimori Ryosho Nakane Department of Electrical Engineering and Information Systems The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan Department of Physics The University of Tokyo Bunkyo-ku Tokyo 113-0033 Japan Materials Sciences Research Center Japan Energy Atomic Agency Sayo Hyogo 679-5148 Japan Department of Quantum Matters ADSM Hiroshima University Higashi-Hiroshima 739-8530 Japan Department of Physics Kyoto Sangyo University Motoyama Kamigamo Kita-Ku Kyoto 603-8555 Japan Center for Spintronics Research Network Graduate School of Engineering The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan Institute for Innovation in International Engineering Education The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan

We study the electronic structure and magnetic properties of epitaxial (Ni1–xCox)Fe2O4(111) layers (x=0–1) with thicknesses d=1.7–5.2nm grown on Al2O3(111)/Si(111) structures, to achieve a high value of inversion parameter y which is the inverse-to-normal spinel-structure ratio, and hence to obtain good magnetic properties even when the thickness is thin enough for electron tunneling as a spin filter. We revealed the crystallographic (octahedral Oh or tetrahedral Td) sites and the valences of the Fe, Co, and Ni cations using experimental soft x-ray absorption spectroscopy and x-ray magnetic circular dichroism spectra and configuration-interaction cluster-model calculation. In all the (Ni1–xCox)Fe2O4 layers with d∼4 nm, all Ni cations occupy the Ni2+(Oh) site, whereas Co cations occupy the three different Co2+(Oh),Co2+(Td), and Co3+(Oh) sites with constant occupancies. According to these features, the occupancy of the Fe3+(Oh) cations decreases and that of the Fe3+(Td) cations increases with decreasing x. Consequently, we obtained a systematic increase of y with decreasing x and achieved the highest y value of 0.91 for the NiFe2O4 layer with d=3.5nm. From the d dependences of y and magnetization in the d range of 1.7–5.2 nm, a magnetically dead layer is present near the NiFe2O4/Al2O3 interface, but its influence on the magnetization was significantly suppressed compared with the case of CoFe2O4 layers reported previously [Wakabayashi et al., Phys. Rev. B 96, 104410 (2017)], due to the high site selectivity of the Ni cations. Since our epitaxial NiFe2O4 layer with d=3.5nm has a high y value (0.91) and a reasonably large magnetization, it is expected to exhibit a strong spin-filter effect which can be used for efficient spin injection into Si.

关键词： Electronic structure of atoms & molecules Ferrimagnetism Interfaces Magnetic insulators Oxides Cluster models Epitaxy X-ray magnetic circular dichroism

quantum tomography of solitary electrons

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arXiv 2019年

作者： Fletcher, J.D. Johnson, N. Locane, E. See, P. Griffiths, J.P. Farrer, I. Ritchie, D.A. Brouwer, P.W. Kashcheyevs, V. Kataoka, M. National Physical Laboratory Hampton Road Teddington MiddlesexTW11 0LW United Kingdom London Centre for Nanotechnology and Department of Electronic and Electrical Engineering University College London Torrington Place LondonWC1E 7JE United Kingdom Dahlem Center for Complex Quantum Systems Institut für Theoretische Physik Freie Universität Berlin Arnimallee 14 Berlin14195 Germany Cavendish Laboratory University of Cambridge J. J. Thomson Avenue CambridgeCB3 0HE United Kingdom Department of Physics University of Latvia Jelgavas street 3 RigaLV 1004 Latvia

Initializing and measuring the wave-function of single freely-propagating particles are challenging but fundamental tasks for applications in quantum information processing and enhanced sensing1-10. Recently, continuous-variable quantum tomography techniques developed for atomic beams11 and photonic modes12 have been adapted for on-demand electronic excitations13-15 but are limited to the region in energy-time phase space immediately around the Fermi level. Here we present a general, broad-band method for mapping the single-particle phase space Wigner distribution. We reconstruct the Wigner representation of the mixed-state density matrix for solitary electrons emitted by an on-demand source. This reveals highly localised distributions isolated from the Fermi sea. Our method can be used to test the degree of 'quantumness' of an electron source from measurements of the phase-space density. While both source purity and detector fidelity are suppressed by classical fluctuations, here we resolve fine structure of the wavepackets (a chirp controlled by emission conditions) and find that the resolution should be sufficient to enable quantum-limited measurements. Our technique will provide key information required to master electron coherence and entanglement at the individual particle level, for instance to create excitations from multiple sources that are indistinguishable16. Copyright © 2019, The Authors. All rights reserved.

关键词： Phase space methods

Nonequilibrium quantum thermodynamics in Coulomb crystals

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Physical Review A 2017年第6期95卷 063615-063615页

作者： F. Cosco M. Borrelli P. Silvi S. Maniscalco G. De Chiara Turku Centre for Quantum Physics Department of Physics and Astronomy University of Turku 20014 Turun yliopisto Finland Institute for Complex Quantum Systems and Center for Integrated Quantum Science and Technologies Universitat Ulm 89069 Ulm Germany Institute for Theoretical Physics University of Innsbruck 6020 Innsbruck Austria Center for Quantum Engineering Department of Applied Physics Aalto University School of Science P.O. Box 11000 00076 Aalto Finland Centre for Theoretical Atomic Molecular and Optical Physics Queen's University Belfast Belfast BT7 1NN United Kingdom

We present an in-depth study of the nonequilibrium statistics of the irreversible work produced during sudden quenches in proximity to the structural linear-zigzag transition of ion Coulomb crystals in 1+1 dimensions. By employing both an analytical approach based on a harmonic expansion and numerical simulations, we show the divergence of the average irreversible work in proximity to the transition. We show that the nonanalytic behavior of the work fluctuations can be characterized in terms of the critical exponents of the quantum Ising chain. Due to the technological advancements in trapped-ion experiments, our results can be readily verified.

关键词： quantum information with trapped ions quantum thermodynamics Trapped ions Density matrix renormalization group

Theory-restricted resonant x-ray reflectometry of quantum materials

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Physical Review B 2018年第16期97卷 165126-165126页

作者： Katrin Fürsich Volodymyr B. Zabolotnyy Enrico Schierle Lenart Dudy Ozan Kirilmaz Michael Sing Ralph Claessen Robert J. Green Maurits W. Haverkort Vladimir Hinkov Physikalisches Institut and Röntgen Center for Complex Material Systems Universität Würzburg 97074 Würzburg Germany Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (HZB) 12489 Berlin Germany Stewart Blusson Quantum Matter Institute University of British Columbia Vancouver V6T 1Z4 Canada Department of Physics & Engineering Physics University of Saskatchewan Saskatoon Saskatchewan S7N 5E2 Canada Institut für Theoretische Physik Universität Heidelberg 69120 Heidelberg Germany

The delicate interplay of competing phases in quantum materials is dominated by parameters such as the crystal field potential, the spin-orbit coupling, and, in particular, the electronic correlation strength. Whereas small quantitative variations of the parameter values can thus qualitatively change the material, these values can hitherto hardly be obtained with reasonable precision, be it theoretically or experimentally. Here we propose a solution combining resonant x-ray reflectivity (RXR) with multiplet ligand field theory (MLFT). We first perform ab initio DFT calculations within the MLFT framework to get initial parameter values, which we then use in a fit of the theoretical model to RXR. To validate our method, we apply it to NiO and SrTiO3 and obtain parameter values, which are amended by as much as 20% compared to the ab initio results. Our approach is particularly useful to investigate topologically trivial and nontrivial correlated insulators, staggered moments in magnetically or orbitally ordered materials, and reconstructed interfaces.

关键词： Electronic structure Refraction Strongly correlated systems Exact solutions for many-body systems quantum chemistry methods Resonant elastic x-ray scattering X-ray absorption spectroscopy