检索结果-内蒙古大学图书馆

Stacking monolayers at will:A scalable device optimization strategy for two-dimensional semiconductors

学校读者我要写书评

暂无评论

Nano Research 2022年第7期15卷 6620-6627页

作者： Xiaojiao Guo Honglei Chen Jihong Bian Fuyou Liao Jingyi Ma Simeng Zhang Xinzhi Zhang Junqiang Zhu Chen Luo Zijian Zhang Lingyi Zong Yin Xia Chuming Sheng Zihan Xu Saifei Gou Xinyu Wang Peng Gong Liwei Liu Xixi Jiang Zhenghua An Chunxiao Cong Zhijun Qiu Xing Wu Peng Zhou Xinyu Chen Ling Tong Wenzhong Bao State Key Laboratory of ASIC and System School of MicroelectronicsZhangjiang Fudan International Innovation CenterFudan UniversityShanghai 200433China The Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518057China Department of Physics State Key Laboratory of Surface PhysicsInstitute of Nanoelectronic Devices and Quantum Computing and Key Laboratory of MicroFudan UniversityShanghai 200433China State Key Laboratory of ASIC and System School of Information Science and EngineeringFudan UniversityShanghai 200433China Shanghai Key Laboratory of Multidimensional Information Processing Department of Electronic Engineering East China Normal UniversityShanghai 200241China Shenzhen Six Carbon Technology Shenzhen 518055China Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Fudan UniversityShanghai 200433China

In comparison to monolayer(1L),multilayer(ML)two-dimensional(2D)semiconducting transition metal dichalcogenides(TMDs)exhibit more application potential for electronic and optoelectronic devices due to their improved current carrying capability,higher mobility,and broader spectral ***,the investigation of devices based on wafer-scale ML-TMDs is still restricted by the synthesis of uniform and high-quality ML *** this work,we propose a strategy of stacking MoS_(2) monolayers via a vacuum transfer method,by which one could obtain wafer-scale high-quality MoS_(2) films with the desired number of layers at *** optical characteristics of these stacked ML-MoS_(2) films(>2L)indicate a weak interlayer *** stacked MLMoS_(2) phototransistors show improved optoelectrical performances and a broader spectral response(approximately 300-1,000 nm)than that of 1L-MoS_(2).Additionally,the dual-gate ML-MoS_(2) transistors enable enhanced electrostatic control over the stacked ML-MoS_(2) channel,and the 3L and 4L thicknesses exhibit the optimal device performances according to the turning point of the current on/off ratio and the subthreshold swing.

关键词： two-dimensional semiconductor field-effect transistors chemical vapor deposition(CVD)synthesis interlayer coupling vacuum transfer method dual-gate transistor

Non-classical microwave-optical photon pair generation with a chip-scale transducer

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Meesala, Srujan Wood, Steven Lake, David Chiappina, Piero Zhong, Changchun Beyer, Andrew D. Shaw, Matthew D. Jiang, Liang Painter, Oskar Kavli Nanoscience Institute and Thomas J. Watson Sr. Laboratory of Applied Physics California Institute of Technology PasadenaCA91125 United States Institute for Quantum Information and Matter California Institute of Technology PasadenaCA91125 United States Pritzker School of Molecular Engineering The University of Chicago ChicagoIL60637 United States Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Dr PasadenaCA91109 United States Center for Quantum Computing Amazon Web Services PasadenaCA91125 United States

Modern computing and communication technologies such as supercomputers and the internet are based on optically connected networks of microwave frequency information processors [1, 2]. In recent years, an analogous architecture has emerged for quantum networks with optically distributed entanglement [3, 4] between remote superconducting quantum processors, a leading platform for quantum computing [5–7]. Here we report an important milestone towards such networks by observing non-classical correlations between photons in an optical link and a superconducting electrical circuit. We generate such states of light through a spontaneous parametric down-conversion (SPDC) process in a chip-scale piezo-optomechanical transducer [8]. The non-classical nature of the emitted light is verified by observing anti-bunching in the microwave state conditioned on detection of an optical photon. Such a transducer can be readily connected to a superconducting quantum processor, and serve as a key building block for optical quantum networks of microwave frequency qubits. © 2023, CC BY.

关键词： Transducers

quantum entanglement between optical and microwave photonic qubits

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Meesala, Srujan Lake, David Wood, Steven Chiappina, Piero Zhong, Changchun Beyer, Andrew D. Shaw, Matthew D. Jiang, Liang Painter, Oskar Kavli Nanoscience Institute and Thomas J. Watson Sr. Laboratory of Applied Physics California Institute of Technology PasadenaCA91125 United States Institute for Quantum Information and Matter California Institute of Technology PasadenaCA91125 United States Pritzker School of Molecular Engineering The University of Chicago ChicagoIL60637 United States Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Dr PasadenaCA91109 United States Center for Quantum Computing Amazon Web Services PasadenaCA91125 United States

Entanglement is an extraordinary feature of quantum mechanics. Sources of entangled optical photons were essential to test the foundations of quantum physics through violations of Bell’s inequalities. More recently, entangled many-body states have been realized via strong non-linear interactions in microwave circuits with superconducting qubits. Here we demonstrate a chip-scale source of entangled optical and microwave photonic qubits. Our device platform integrates a piezo-optomechanical transducer with a superconducting resonator which is robust under optical illumination. We drive a photon-pair generation process and employ a dual-rail encoding intrinsic to our system to prepare entangled states of microwave and optical photons. We place a lower bound on the fidelity of the entangled state by measuring microwave and optical photons in two orthogonal bases. This entanglement source can directly interface telecom wavelength time-bin qubits and GHz frequency superconducting qubits, two well-established platforms for quantum communication and computation, respectively. Copyright © 2023, The Authors. All rights reserved.

关键词： quantum entanglement

Microwave-Optical Entanglement from Pulse-pumped Electro-optomechanics

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Zhong, Changchun Li, Fangxin Meesala, Srujan Wood, Steven Lake, David Painter, Oskar Jiang, Liang Department of Physics Xi’an Jiaotong University Shanxi Xi’an710049 China Department of Physics University of Chicago ChicagoIL60637 United States Institute for Quantum Information and Matter California Institute of Technology PasadenaCA91125 United States Kavli Nanoscience Institute and Thomas J. Watson Sr. Laboratory of Applied Physics California Institute of Technology PasadenaCA91125 United States Center for Quantum Computing Amazon Web Services PasadenaCA91125 United States Pritzker School of Molecular Engineering University of Chicago ChicagoIL60637 United States

Entangling microwave and optical photons is one of the promising ways to realize quantum transduction through quantum teleportation. This paper investigates the entanglement of microwave-optical photon pairs generated from an electro-optomechanical system driven by a blue-detuned pulsed Gaussian pump. The photon pairs are obtained through weak parametric-down-conversion, and their temporal correlation is revealed by the second-order correlation function. We then study the discrete variable entanglement encoded in the time bin degree of freedom, where entanglement is identified by Bell inequality violation. Furthermore, we estimate the laser-induced heating and show that the pulse-pumped system features lower heating effects while maintaining a reasonable coincidence photon counting rate. © 2024, CC BY.

关键词： quantum entanglement

Scalable entanglement of nuclear spins mediated by electron exchange

学校读者我要写书评

暂无评论

arXiv 2025年

作者： Stemp, Holly G. van Blankenstein, Mark R. Asaad, Serwan Mądzik, Mateusz T. Joecker, Benjamin Firgau, Hannes R. Laucht, Arne Hudson, Fay E. Dzurak, Andrew S. Itoh, Kohei M. Jakob, Alexander M. Johnson, Brett C. Jamieson, David N. Morello, Andrea School of Electrical Engineering and Telecommunications UNSW Sydney SydneyNSW2052 Australia ARC Centre of Excellence for Quantum Computation and Communication Technology NNF Quantum Computing Programme Niels Bohr Institute University of Copenhagen Denmark Diraq Pty. Ltd. SydneyNSW Australia School of Fundamental Science and Technology Keio University Kohoku-ku Yokohama Japan School of Physics University of Melbourne MelbourneVIC3010 Australia School of Science RMIT University MelbourneVIC3000 Australia

The use of nuclear spins for quantum computation is limited by the difficulty in creating genuine quantum entanglement between distant nuclei. Current demonstrations of nuclear entanglement in semiconductors rely upon coupling the nuclei to a common electron, which is not a scalable strategy. Here we demonstrate a two-qubit Control-Z logic operation between the nuclei of two phosphorus atoms in a silicon device, separated by up to 20 nanometers. Each atoms binds separate electrons, whose exchange interaction mediates the nuclear two-qubit gate. We prove that the nuclei are entangled by preparing and measuring Bell states with a fidelity of 76+5−5% and a concurrence of 0.67+0.05−0.05. With this method, future progress in scaling up semiconductor spin qubits can be extended to the development of nuclear-spin based quantum computers. © 2025, CC BY-NC-ND.

关键词： Qubits

quantum uncertainty as classical uncertainty of real-deterministic variables constructed from complex weak values and a global random variable

学校读者我要写书评

暂无评论

Physical Review A 2021年第2期103卷 022215-022215页

作者： Agung Budiyono Hermawan K. Dipojono Research Center for Nanoscience and Nanotechnology Bandung Institute of Technology Bandung 40132 Indonesia Department of Engineering Physics Bandung Institute of Technology Bandung 40132 Indonesia Laboratory for Quantum Technology School of Electrical Engineering and Informatics Bandung Institute of Technology Bandung 40132 Indonesia Kubus Computing and Research Juwana Pati 59185 Indonesia

What does it take for real-deterministic c-valued (i.e., classical, commuting) variables to comply with the Heisenberg uncertainty principle? Here, we construct a class of real-deterministic c-valued variables out of the weak values obtained via a nonperturbing weak measurement of quantum operators with a postselection over a complete set of state vectors basis, which always satisfies the Kennard-Robertson-Schrödinger uncertainty relation. First, we introduce an auxiliary global random variable and couple it to the imaginary part of the weak value to convert the incompatibility between the quantum operator and the basis into the fluctuation of an “error term,” and then superimpose it onto the real part of the weak value. We show that this class of “c-valued physical quantities” provides a real-deterministic contextual hidden-variable model for the quantum expectation value of a certain class of operators. We then show that the Schrödinger and the Kennard-Robertson lower bounds can be obtained separately by imposing the classical uncertainty relation to the c-valued physical quantities associated with a pair of Hermitian operators. Within the representation, the complementarity between two incompatible quantum observables manifests the absence of a basis wherein the error terms of the associated two c-valued physical quantities simultaneously vanish. Furthermore, quantum uncertainty principle is captured by a specific irreducible epistemic restriction between the two c-valued physical quantities, foreign in classical mechanics, constraining the allowed form of their joint distribution. We then suggest an epistemic interpretation of the two terms decomposing the c-valued physical quantity as the optimal estimate under the epistemic restriction and the associated estimation error, and discuss the classical limit.

关键词： quantum formalism quantum foundations quantum measurements quantum parameter estimation quantum-to-classical transition

Topological Spin Texture of Chiral Edge States in Photonic Two-Dimensional quantum Walks

学校读者我要写书评

暂无评论

Physical Review Letters 2022年第4期129卷 046401-046401页

作者： Chao Chen Xing Ding Jian Qin Jizhou Wu Yu He Chao-Yang Lu Li Li Xiong-Jun Liu Barry C. Sanders Jian-Wei Pan Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics University of Science and Technology of China Shanghai Branch Shanghai 201315 China CAS-Alibaba Quantum Computing Laboratory CAS Centre for Excellence in Quantum Information and Quantum Physics Shanghai 201315 China National Laboratory of Solid State Microstructures School of Physics Nanjing University Nanjing 210093 China Shenzhen Institute for Quantum Science and Engineering Southern University of Science and Technology Shenzhen 518055 China International Center for Quantum Materials and School of Physics Peking University Beijing 100871 China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing 100190 China Institute for Quantum Science and Technology University of Calgary Alberta T2N 1N4 Canada

Topological insulators host topology-linked boundary states, whose spin and charge degrees of freedom could be exploited to design topological devices with enhanced functionality. We experimentally observe that dissipationless chiral edge states in a spin-orbit coupled anomalous Floquet topological phase exhibit topological spin texture on boundaries, realized via a two-dimensional quantum walk. Our experiment shows that, for a walker traveling around a closed loop along the boundary in real space, its spin evolves and winds through a great circle on the Bloch sphere, which implies that edge-spin texture has nontrivial winding. This topological spin winding is protected by a chiral-like symmetry emerging for the low-energy Hamiltonian. Our experiment confirms that two-dimensional anomalous Floquet topological systems exhibit topological spin texture on the boundary, which could inspire novel topology-based spintronic phenomena and devices.

关键词： Edge states Photonics quantum walks Spin texture Topological phases of matter

Learning k-body Hamiltonians via compressed sensing

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Ma, Muzhou Flammia, Steven T. Preskill, John Tong, Yu Institute for Quantum Information and Matter California Institute of Technology CA91125 United States Department of Computer Science Virginia Tech AlexandriaVA22314 United States Phasecraft Inc. WashingtonDC20001 United States Department of Mathematics Duke University DurhamNC27708 United States Department of Electrical and Computer Engineering Duke University DurhamNC27708 United States Department of Electronic Engineering Tsinghua University Beijing China AWS Center for Quantum Computing PasadenaCA91125 United States

We study the problem of learning a k-body Hamiltonian with M unknown Pauli terms that are not necessarily geometrically local. We propose a protocol that learns the Hamiltonian to precision ϵ with total evolution time O(M1/2+1/p/ϵ) up to logarithmic factors, where the error is quantified by the p-distance between Pauli coefficients. Our learning protocol uses only single-qubit control operations and a GHZ state initial state, is non-adaptive, is robust against SPAM errors, and performs well even if M and k are not precisely known in advance or if the Hamiltonian is not exactly M-sparse. Methods from the classical theory of compressed sensing are used for efficiently identifying the M terms in the Hamiltonian from among all possible k-body Pauli operators. We also provide a lower bound on the total evolution time needed in this learning task, and we discuss the operational interpretations of the 1 and 2 error metrics. In contrast to most previous works, our learning protocol requires neither geometric locality nor any other relaxed locality conditions. © 2024, CC BY-SA.

关键词： Hamiltonians

Coherence fraction in Grover's search algorithm

学校读者我要写书评

暂无评论

Physical Review A 2024年第6期110卷 062429-062429页

作者： Si-Qi Zhou Hai Jin Jin-Min Liang Shao-Ming Fei Yunlong Xiao Zhihao Ma School of Mathematical Sciences MOE-LSC Shanghai Jiao Tong University Shanghai 200240 China Shanghai Seres Information Technology Co. Ltd Shanghai 200040 China Shenzhen Institute for Quantum Science and Engineering Southern University of Science and Technology Shenzhen 518055 China State Key Laboratory for Mesoscopic Physics School of Physics Frontiers Science Center for Nano-Optoelectronics Peking University Beijing 100871 China School of Mathematical Sciences Capital Normal University Beijing 100048 China Max Planck Institute for Mathematics in the Sciences - 04103 Leipzig Germany Quantum Innovation Centre (Q.InC) Agency for Science Technology and Research (ASTAR) 2 Fusionopolis Way Innovis #08-03 Singapore 138634 Republic of Singapore Institute of High Performance Computing (IHPC) Agency for Science Technology and Research (ASTAR) 1 Fusionopolis Way #16-16 Connexis Singapore 138632 Republic of Singapore

The question of which resources drive the advantages in quantum algorithms has long been a fundamental challenge. While entanglement and coherence are critical to many quantum algorithms, our results indicate that they do not fully explain the quantum advantage achieved by the Grover search algorithm. By introducing a generalized Grover search algorithm, we demonstrate that the success probability depends not only on the querying number of oracles but also on the coherence fraction, which quantifies the fidelity between an arbitrary initial quantum state and the equal superposition state. Additionally, we explore the role of the coherence fraction in the quantum minimization algorithm, which offers a framework for solving complex problems in quantum machine learning. These findings offer insights into the origins of quantum advantage and open pathways for the development of new quantum algorithms.

关键词： quantum entanglement