检索结果-内蒙古大学图书馆

Thermally tunable high Q-factor and low-power silicon resonators using Graphene transparent electrodes

Thermally tunable high Q-factor and low-power silicon resona...

2023 Applied Optics and Photonics China: Laser Technology and Applications;and Optoelectronic Devices and Integration, AOPC 2023

作者： Hong, Qilin Xu, Ping Xu, Wei Zhu, Zhihong College of Advanced Interdisciplinary Studies Hunan Provincial Key Laboratory of Novel Nano Optoelectronic Information Materials and Devices National University of Defense Technology Changsha410073 China Nanhu Laser Laboratory National University of Defense Technology Changsha410073 China Institute for Quantum Information State Key Laboratory of High-Performance Computing College of Computer Science and Technology National University of Defense Technology Changsha410073 China

ISBN: (纸本)9781510672246

Tunable and low-power microcavities play a vital role in facilitating the development of large-scale photonic integrated circuits. Among various tuning methods, thermal tuning has gained significant popularity due to its convenience and stability, especially in the fields of optical neural networks and quantum information processing. In recent years, graphene thermal tuning has emerged as a promising technique, offering both tunability and power efficiency by eliminating the need for thick spacers to prevent light absorption. In this study, we propose and fabricate a silicon-based on-chip Fano resonator with graphene nano-heaters. This innovative Fano structure incorporates a scattering block and can be easily manufactured in large quantities. Experimental results demonstrate that the resonator exhibits desirable characteristics, including a high quality factor of approximately 31000 and a low state-switching power consumption of around 1 mW. The temporal responses of the microcavity exhibit satisfactory modulation speed, with a rise time of 9.8 µs and a fall time of 16.6 µs. The findings of this research offer an alternative solution for the future development of large-scale tunable and low-power-consumption optical networks, with potential applications in optical filters and switches. © 2023 SPIE.

关键词： Graphene

来源：评论

学校读者我要写书评

暂无评论

Photon orbits and phase transition for Letelier AdS black holes immersed in perfect fluid dark matter

引用

Chinese Physics C 2024年第6期48卷 247-259页

作者： Ashima Sood Md Sabir Ali J.K.Singh Sushant G.Ghosh Department of Mathematics Netaji Subhas University of TechnologyNew Delhi-110078India Centre for Theoretical Physics Jamia Millia IslamiaNew Delhi 110025India Department of Physics Mahishadal Raj CollegePurba MedinipurWest Bengal721628India Institute of Theoretical Physics&Research Center of Gravitation Lanzhou UniversityLanzhou 730000China Key Laboratory of Quantum Theory and Applications of MoE Lanzhou UniversityLanzhou 730000China Lanzhou Center for Theoretical Physics&Key Laboratory of Theoretical Physics of Gansu Province Lanzhou UniversityLanzhou 730000China Astrophysics and Cosmology Research Unit School of MathematicsStatistics and Computer ScienceUniversity of KwaZulu-NatalPrivate Bag X54001Durban 4000South Africa

We obtain an exact solution for spherically symmetric Letelier AdS black holes immersed in perfect fluid dark matter(PFDM).Considering the cosmological constant as the positive pressure of the system and volume as its conjugate variable,we analyze the thermodynamics of our black holes in the extended phase *** to the background clouds of strings parameter(a)and the parameter endowed with PFDM(β),we analyze the Hawking temperature,entropy,and specific ***,we investigate the relationship between the photon sphere radius and phase transition for the Letelier AdS black holes immersed in *** the analysis,with a particular condition,non-monotonic behaviors are found between the photon sphere radius,impact parameter,PFDM parameter,temperature,and *** can regard the changes in both the photon sphere radius and impact parameter before and after phase transition as the order parameter;their critical exponents near the critical point are equal to the same value,1/2,similar to that in ordinary thermal *** indicates that a universal relation of gravity may exist near the critical point for a black hole thermodynamic system.

关键词： AdS black holes perfect fluid dark matter Letelier spacetime photon orbit extended phase space thermodynamics correlation of photon orbit and thermodynamics

来源：评论

学校读者我要写书评

暂无评论

LazyDB: I/O Optimization of Blockchain Storage System Based on Non-Volatile Memory

LazyDB: I/O Optimization of Blockchain Storage System Based ...

引用

Information science, Parallel and Distributed Systems (ISPDS), International Conference on

作者： Yang Liu Xuran Ge Nong Xiao Zhiguang Chen Yang Ou State Key Laboratory of High-Performance Computing Institute for Quantum Information College of Computer National University of Defense Technology Changsha China School of computer science and Engineering Sun Yat-sen University Guangzhou China College of Computer National University of Defense Technology Changsha China

For the blockchain storage system, this paper proposes an I/O optimization scheme based on non-volatile memory based on the storage performance requirements of the blockchain system application. This scheme adopts the key-value separation strategy. Due to the uncertain size of transaction data, by separating the “key” and “value” of transaction data, the inherent read-write amplification problem of the LSM-Tree structure is solved. The key-value separation strategy redesigns the storage system's space management and garbage collection mechanisms. Therefore, this chapter uses the byte-addressing characteristics of non-volatile memory to build a new data storage structure, a lazy compression mechanism, and a lazy garbage collection mechanism. On this basis, this paper builds a LazyDB database system for blockchain storage. To ensure the safe and reliable operation of the blockchain system, it can make full use of the storage medium and data characteristics, reducing the blockchain reading and writing process. The I/O overhead in the storage system improves the storage performance of the system. The experimental results show that compared with the most commonly used databases, such as LevelDB and RocksDB in the blockchain system, LazyDB effectively reduces the write amplification of the system and has higher read, write, and data update performance.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Self-supervised representation learning for Bayesian quantum architecture search

引用

Physical Review A 2025年第3期111卷 032403-032403页

作者： Zhimin He Hongxiang Chen Yan Zhou Haozhen Situ Yongyao Li Lvzhou Li School of Electronic and Information Engineering Foshan University Foshan 528000 China School of Computer Science and Artificial Intelligence Foshan University Foshan 528000 China Guangdong Provincial Key Laboratory of Industrial Intelligent Inspection Technology Foshan University Foshan 528000 China College of Mathematics and Informatics South China Agricultural University Guangzhou 510642 China School of Physics and Optoelectronic Engineering Foshan University Foshan 528225 China Institute of Quantum Computing and Software School of Computer Science and Engineering Sun Yat-sen University Guangzhou 510006 China Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (Guangdong) Shenzhen 518045 China

quantum architecture search (QAS) has shown significant promise in automating quantum circuit design for variational quantum algorithms (VQAs). However, a central challenge remains in the high computational cost of evaluating the ground-truth performance of numerous circuit architectures during the search process. This challenge is further complicated by factors such as inefficient gradient computation, the barren plateau phenomenon, and frequent data exchange between classical and quantum systems within VQAs, all of which restrict the scalability of QAS for increasingly complex VQAs. In this study, we propose an enhanced QAS framework that integrates a performance predictor trained through self-supervised learning with Bayesian optimization to overcome these computational barriers. To address the challenges of circuit performance evaluation, we develop a graph-isomorphism-network-based predictor pretrained using expressibility prediction, an intrinsic measure of a circuit's capacity to explore the Hilbert space uniformly. This pretraining process creates a structured and smooth latent space, significantly improving the predictor's accuracy and generalizability with minimal labeled data. Furthermore, Bayesian optimization is integrated into the QAS framework to refine the predictor iteratively, concentrating the search on regions containing high-performance circuits and thus accelerating the search process. Simulation results for VQAs involving the variational quantum eigensolver and quantum approximate optimization algorithm demonstrate that the proposed framework achieves faster convergence to optimal circuits and substantially reduces computational costs compared to existing QAS methods.

关键词： Bayesian networks

来源：评论

学校读者我要写书评

暂无评论

Succinct quantum testers for closeness and k-wise uniformity of probability distributions

arXiv

引用

arXiv 2023年

作者： Luo, Jingquan Wang, Qisheng Li, Lvzhou Institute of Quantum Computing and Software School of Computer Science and Engineering Sun Yat-sen University Guangzhou510006 China Graduate School of Mathematics Nagoya University Nagoya464-8602 Japan Shenzhen518045 China

We explore potential quantum speedups for the fundamental problem of testing the properties of closeness and k-wise uniformity of probability distributions. • Closeness testing is the problem of distinguishing whether two n-dimensional distributions are identical or at least Ε-far in 1- or 2-distance. We show that the quantum query complexities for 1- and 2-closeness testing are O(√n/Ε) and O(1/Ε), respectively, both of which achieve optimal dependence on Ε, improving the prior best results of Gilyén and Li (2020). • k-wise uniformity testing is the problem of distinguishing whether a distribution over {0, 1}n is uniform when restricted to any k coordinates or Ε-far from any such distribution. We propose the first quantum algorithm for this problem with query complexity O(√nk/Ε), achieving a quadratic speedup over the state-of-the-art classical algorithm with sample complexity O(nk/Ε2) by O'Donnell and Zhao (2018). Moreover, when k = 2 our quantum algorithm outperforms any classical one because of the classical lower bound Ω(n/Ε2). All our quantum algorithms are fairly simple and time-efficient, using only basic quantum subroutines such as amplitude estimation. Copyright © 2023, The Authors. All rights reserved.

关键词： Probability distributions

来源：评论

学校读者我要写书评

暂无评论

Characterization of Intensity Correlation via Single-photon Detection in quantum Key Distribution

arXiv

引用

arXiv 2024年

作者： Xing, Tianyi Liu, Junxuan Zhang, Likang Wang, Min-Yan Li, Yu-Huai Liu, Ruiyin Peng, Qingquan Wang, Dongyang Wang, Yaxuan Liu, Hongwei Li, Wei Cao, Yuan Huang, Anqi Institute for Quantum Information State Key Laboratory of High Performance Computing College of Computer Science and Technology National University of Defense Technology Changsha410073 China Hefei National Research Center for Physical Sciences The Microscale and School of Physical Sciences University of Science and Technology of China Hefei230026 China Shanghai Research Center for Quantum Science CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of China Shanghai201315 China Hefei National Laboratory University of Science and Technology of China Hefei230088 China China Information Technology Security Evaluation Center Beijing100085 China

One of the most significant vulnerabilities in the source unit of quantum key distribution (QKD) is the correlation between quantum states after modulation, which shall be characterized and evaluated for its practical security performance. In this work, we propose a methodology to characterize the intensity correlation according to the single-photon detection results in the measurement unit without modifying the configuration of the QKD system. In contrast to the previous research that employs extra classical optical detector to measure the correlation, our method can directly analyse the detection data generated during the raw key exchange, enabling to characterize the feature of correlation in real-time system operation. The basic method is applied to a BB84 QKD system and the characterized correlation significantly decreases the secure key rate shown by the security proof. Furthermore, the method is extended and applied to characterize the correlation from the result of Bell-state measurement, which demonstrates its applicability to a running full-scheme MDI QKD system. This study provides an approach for standard certification of a QKD system. Copyright © 2024, The Authors. All rights reserved.

关键词： Photons

来源：评论

学校读者我要写书评

暂无评论

quantum Simulation of the First-Quantized Pauli-Fierz Hamiltonian

arXiv

引用

arXiv 2023年

作者： Mukhopadhyay, Priyanka Stetina, Torin F. Wiebe, Nathan Department of Physical & Environmental Sciences University of Toronto ON Canada Simons Institute for the Theory of Computing BerkeleyCA United States Berkeley Quantum Information and Computation Center University of California Berkeley United States Department of Computer Science University of Toronto ON Canada Pacific Northwest National Laboratory RichlandWA United States Canadian Institute for Advanced Research TorontoON Canada

We provide an explicit recursive divide and conquer approach for simulating quantum dynamics and derive a discrete first quantized non-relativistic QED Hamiltonian based on the many-particle Pauli Fierz Hamiltonian. We apply this recursive divide and conquer algorithm to this Hamiltonian and compare it to a concrete simulation algorithm that uses qubitization. Our divide and conquer algorithm, using lowest order Trotterization, scales for fixed grid spacing as Õ(ΛN2η2t2/ϵ) for grid size N, η particles, simulation time t, field cutoff Λ and error ϵ. Our qubitization algorithm scales as Õ(N(η + N)(η + Λ2)tlog(1/ϵ)). This shows that even a naïve partitioning and low-order splitting formula can yield, through our divide and conquer formalism, superior scaling to qubitization for large Λ. We compare the relative costs of these two algorithms on systems that are relevant for applications such as the spontaneous emission of photons, and the photoionization of electrons. We observe that for different parameter regimes, one method can be favored over the other. Finally, we give new algorithmic and circuit level techniques for gate optimization including a new way of implementing a group of multi-controlled-X gates that can be used for better analysis of circuit cost. © 2023, CC BY.

关键词： Hamiltonians

来源：评论

学校读者我要写书评

暂无评论

isQ: Towards a Practical Software Stack for quantum Programming

arXiv

引用

arXiv 2022年

作者： Guo, Jingzhe Lou, Huazhe Li, Riling Fang, Wang Liu, Junyi Long, Peixun Ying, Shenggang Ying, Mingsheng Department of Computer Science and Technology Tsinghua University Beijing China Arclight Quantum Computing Inc Beijing China State Key Laboratory of Computer Science Institute of Software Chinese Academy of Sciences Beijing China

We introduce isQ, a new software stack for quantum programming in an imperative programming language, also named isQ. The aim of isQ is to make the programmers write quantum programs as conveniently as possible. In particular: 1) The isQ language and its compiler contain many features, including some not well supported by (most) other quantum programming platforms, e.g. classical control flow such as recursion;decomposition of self-defined unitary gates;and oracle programming and its circuit realization. 2) To make it flexible, an isQ program can be compiled into several kinds of intermediate representation, including OpenQASM 3.0, QIR and QCIS (specially tailored for the superconducting quantum hardware at USTC). 3) Besides interfacing isQ with true superconducting hardware, a QIR simulator is also developed for demonstration and testing of isQ programs. © 2022, CC BY.

关键词： Program compilers

来源：评论

学校读者我要写书评

暂无评论

quantum Depth in the Random Oracle Model

arXiv

引用

arXiv 2022年

作者： Arora, Atul Singh Coladangelo, Andrea Coudron, Matthew Gheorghiu, Alexandru Singh, Uttam Waldner, Hendrik Institute for Quantum Information and Matter California Institute of Technology Department of Computing and Mathematical Sciences California Institute of Technology United States University of California Berkeley Simons Institute The Theory of Computing United States Department of Computer Science University of Maryland United States Department of Computer Science and Engineering Chalmers University of Technology Institute for Theoretical Studies ETH Zürich Switzerland Center for Theoretical Physics Polish Academy of Sciences Poland Department of Computer Science University of Maryland Max Planck Institute for Security and Privacy United States

We give a comprehensive characterization of the computational power of shallow quantum circuits combined with classical computation. Specifically, for classes of search problems, we show that the following statements hold, relative to a random oracle: (a) BPPQNCBPP ≠ BQP. This refutes Jozsa's conjecture [Joz05] in the random oracle model. As a result, this gives the first instantiatable separation between the classes by replacing the oracle with a cryptographic hash function, yielding a resolution to one of Aaronson's ten semi-grand challenges in quantum computing [Aar05]. (b) BPPQNC ⊆ QNCBPP and QNCBPP ⊆ BPPQNC. This shows that there is a subtle interplay between classical computation and shallow quantum computation. In fact, for the second separation, we establish that, for some problems, the ability to perform adaptive measurements in a single shallow quantum circuit, is more useful than the ability to perform polynomially many shallow quantum circuits without adaptive measurements. (c) There exists a 2-message proof of quantum depth protocol. Such a protocol allows a classical verifier to efficiently certify that a prover must be performing a computation of some minimum quantum depth. Our proof of quantum depth can be instantiated using the recent proof of quantumness construction by Yamakawa and Zhandry [YZ22]. Copyright © 2022, The Authors. All rights reserved.

关键词： Hash functions

来源：评论

学校读者我要写书评

暂无评论

quantum Phase Estimation by Compressed Sensing

arXiv

引用

arXiv 2023年

作者： Yi, Changhao Zhou, Cunlu Takahashi, Jun State Key Laboratory of Surface Physics Department of Physics Center for Field Theory and Particle Physics Fudan University Shanghai China Institute for Nanoelectronic Devices and Quantum Computing Fudan University Shanghai China Shanghai Research Center for Quantum Sciences Shanghai China Department of Computer Science & Institut Quantique Université de Sherbrooke QC Canada Center for Quantum Information and Control Department of Physics and Astronomy University of New Mexico NM United States Institute of Solid State Physics University of Tokyo Chiba Japan

As a signal recovery algorithm, compressed sensing is particularly effective when the data has low complexity and samples are scarce, which aligns natually with the task of quantum phase estimation (QPE) on early fault-tolerant quantum computers. In this work, we present a new Heisenberg-limited, robust QPE algorithm based on compressed sensing, which requires only sparse and discrete sampling of times. Specifically, given multiple copies of a suitable initial state and queries to a specific unitary matrix, our algorithm can recover the phase with a total runtime of O(ϵ−1poly log(ϵ−1)), where ϵ is the desired accuracy. Additionally, the maximum runtime satisfies Tmaxϵ π, making it comparable to state-of-the-art algorithms. Furthermore, our result resolves the basis mismatch problem in certain cases by introducing an additional parameter to the traditional compressed sensing framework. © 2023, CC BY.

关键词： Fault tolerant computer systems

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：