检索结果-内蒙古大学图书馆

Giant Cross–Kerr Effect for Propagating Microwaves Induced by an Artificial Atom

Physical Review Letters 2013年第5期111卷 053601-053601页

作者： Io-Chun Hoi Anton F. Kockum Tauno Palomaki Thomas M. Stace Bixuan Fan Lars Tornberg Sankar R. Sathyamoorthy Göran Johansson Per Delsing C. M. Wilson Department of Microtechnology and Nanoscience (MC2) Chalmers University of Technology SE-412 96 Göteborg Sweden Centre for Engineered Quantum Systems School of Physical Sciences University of Queensland Saint Lucia Queensland 4072 Australia Institute for Quantum Computing and Electrical and Computer Engineering Department University of Waterloo Waterloo N2L 3G1 Canada

We investigate the effective interaction between two microwave fields, mediated by a transmon-type superconducting artificial atom which is strongly coupled to a coplanar transmission line. The interaction between the fields and atom produces an effective cross–Kerr coupling. We demonstrate average cross–Kerr phase shifts of up to 20 degrees per photon with both coherent microwave fields at the single-photon level. Our results provide an important step toward quantum applications with propagating microwave photons.

关键词： MICROWAVE photonics ATOMS PARTICLE interactions KERR electro-optical effect SUPERCONDUCTING composites COPLANAR transmission lines SINGLE photon generation

来源：评论

学校读者我要写书评

暂无评论

Universal Slow Growth of Entanglement in Interacting Strongly Disordered Systems

引用

Physical Review Letters 2013年第26期110卷 260601-260601页

作者： Maksym Serbyn Z. Papić Dmitry A. Abanin Department of Physics Massachusetts Institute of Technology Cambridge Massachusetts 02138 USA Department of Electrical Engineering Princeton University Princeton New Jersey 08544 USA Perimeter Institute for Theoretical Physics Waterloo Ontario N2L 2Y5 Canada Institute for Quantum Computing Waterloo Ontario N2L 3G1 Canada

Recent numerical work by Bardarson, Pollmann, and Moore revealed a slow, logarithmic in time, growth of the entanglement entropy for initial product states in a putative many-body localized phase. We show that this surprising phenomenon results from the dephasing due to exponentially small interaction-induced corrections to the eigenenergies of different states. For weak interactions, we find that the entanglement entropy grows as ξln (Vt/ℏ), where V is the interaction strength, and ξ is the single-particle localization length. The saturated value of the entanglement entropy at long times is determined by the participation ratios of the initial state over the eigenstates of the subsystem. Our work shows that the logarithmic entanglement growth is a universal phenomenon characteristic of the many-body localized phase in any number of spatial dimensions, and reveals a broad hierarchy of dephasing time scales present in such a phase.

关键词： quantum entanglement quantum entropy LOGARITHMS COMPUTER simulation FERMIONS

来源：评论

学校读者我要写书评

暂无评论

Local Conservation Laws and the Structure of the Many-Body Localized States

引用

Physical Review Letters 2013年第12期111卷 127201-127201页

We construct a complete set of local integrals of motion that characterize the many-body localized (MBL) phase. Our approach relies on the assumption that local perturbations act locally on the eigenstates in the MBL phase, which is supported by numerical simulations of the random-field XXZ spin chain. We describe the structure of the eigenstates in the MBL phase and discuss the implications of local conservation laws for its nonequilibrium quantum dynamics. We argue that the many-body localization can be used to protect coherence in the system by suppressing relaxation between eigenstates with different local integrals of motion.

关键词： CONSERVATION laws (Physics) MANY-body problem INTEGRALS PERTURBATION (quantum dynamics) EIGENFUNCTIONS

来源：评论

学校读者我要写书评

暂无评论

Biomimetic sensing by the photoreceptor membrane protein bacteriorhodopsin

引用

Journal of the National institute of Information and Communications technology 2013年第1期60卷 75-83页

作者： Kasai, Katsuyuki Haruyama, Yoshihiro Yamada, Toshiki Akiba, Makoto Tominari, Yukihiro Kaji, Takahiro Terui, Toshifumi Peper, Ferdinand Katagiri, Yoshitada Tanaka, Shukichi Kikuchi, Hiroshi Okada-Shudo, Yoshiko Otomo, Akira Nano ICT Laboratory Department of Quantum Optics Nonlinear Optics Laser Control Advanced ICT Research Institute Japan Nano ICT Laboratory Department of Bio-Materials Advanced ICT Research Institute Japan Nano ICT Laboratory Department of Organic Materials Material Physics Optical Measurement Nano Materials Advanced ICT Research Institute Japan Planning Office Department of Photodetection Technology Semiconductor Device Low-Noise Technology Advanced ICT Research Institute Japan Nano ICT Laboratory Department of Superconductor Organic Electronics Terahertz Advanced ICT Research Institute Japan Nano ICT Laboratory Department of Laser Photochemistry Single-Molecule Spectroscopy Nanophotonics Advanced ICT Research Institute Japan Strategic Planning Office Strategic Planning Department Japan Brain Networks and Communication Laboratory Department of Nanocomputer Architectures Cellular Automata Neural Networks Natural Computing Center for Information and Neural Networks Japan Brain Networks and Communication Laboratory Department of Health Science and Informatics Human Informatics Center for Information and Neural Networks Japan Nano ICT Laboratory Terahertz Technology Research Center Advanced ICT Research Institute Japan Japan Graduate School of Informatics and Engineering Dept. of Engneering Science Japan Nano ICT Laboratory Depatment of Nanophotonics Nonlinear Optics Advanced ICT Research Institute Japan

Bacteriorhodopsin (bR) is a light-sensitive protein which has a proton-pump function, and is found in the cell membrane of Halobacterium salinarum inhabiting the salt lake. Optical excitation of bR at an electrode-electrolyte interface generates differential photocurrents while an incident light is turned on and off. This unique functional response is similar to that seen in retinal neurons. This paper describes the fabrication and evaluation of the dip-coated bR thin films, photocurrent characteristics, and biomimetic artificial retinas with the bR thin films.

关键词： Biomimetics

来源：评论

学校读者我要写书评

暂无评论

Parallel Information Transfer in a Multinode quantum Information Processor

引用

Physical Review Letters 2012年第14期108卷 140502-140502页

作者： T. W. Borneman C. E. Granade D. G. Cory Department of Nuclear Science and Engineering Massachusetts Institute of Technology Cambridge Massachusetts USA Institute for Quantum Computing Waterloo ON Canada Department of Physics University of Waterloo Waterloo ON Canada Perimeter Institute for Theoretical Physics Waterloo ON Canada Department of Chemistry University of Waterloo Waterloo ON Canada

We describe a method for coupling disjoint quantum bits (qubits) in different local processing nodes of a distributed node quantum information processor. An effective channel for information transfer between nodes is obtained by moving the system into an interaction frame where all pairs of cross-node qubits are effectively coupled via an exchange interaction between actuator elements of each node. All control is achieved via actuator-only modulation, leading to fast implementations of a universal set of internode quantum gates. The method is expected to be nearly independent of actuator decoherence and may be made insensitive to experimental variations of system parameters by appropriate design of control sequences. We show, in particular, how the induced cross-node coupling channel may be used to swap the complete quantum states of the local processors in parallel.

关键词： KNOWLEDGE transfer (Communication) quantum information science QUBITS INFORMATION processing ACTUATORS GATE array circuits MODULATION (Electronics) COHERENT states

来源：评论

学校读者我要写书评

暂无评论

Fabrication of CMOS-compatible nanopillars for smart bio-mimetic CMOS image sensors

Fabrication of CMOS-compatible nanopillars for smart bio-mim...

引用

Annual IEEE Northeast Workshop on Circuits and Systems (NEWCAS)

作者： Fayçal Saffih Amro M. Elshurafa Mohammad Ali Mohammad Nathaniel Nelson-Fitzpatrick Stephane Evoy Physical Science and Engineering King Abdullah University for Science and Technology Thuwal Saudi Arabia Department of Electrical and Computer Engineering ECERF W2-085 University of Alberta Edmonton AB Canada Institute for Quantum Computing University of Waterloo Waterloo ONT Canada

In this paper, nanopillars with heights of 1μm to 5μm and widths of 250nm to 500nm have been fabricated with a near room temperature etching process. The nanopillars were achieved with a continuous deep reactive ion etching technique and utilizing PMMA (polymethylmethacrylate) and Chromium as masking layers. As opposed to the conventional Bosch process, the usage of the unswitched deep reactive ion etching technique resulted in nanopillars with smooth sidewalls with a measured surface roughness of less than 40nm. Moreover, undercut was nonexistent in the nanopillars. The proposed fabrication method achieves etch rates four times faster when compared to the state-of-the-art, leading to higher throughput and more vertical side walls. The fabrication of the nanopillars was carried out keeping the CMOS process in mind to ultimately obtain a CMOS-compatible process. This work serves as an initial step in the ultimate objective of integrating photo-sensors based on these nanopillars seamlessly along with the controlling transistors to build a complete bio-inspired smart CMOS image sensor on the same wafer.

关键词： Etching Fabrication Silicon Nanobioscience CMOS integrated circuits Biomedical imaging Educational institutions

来源：评论

学校读者我要写书评

暂无评论

quantum Algorithm for Data Fitting

引用

Physical Review Letters 2012年第5期109卷 050505-050505页

作者： Nathan Wiebe Daniel Braun Seth Lloyd Institute for Quantum Computing and Department of Combinatorics and Optimization University of Waterloo 200 University Ave. West Waterloo Ontario Canada Laboratoire de Physique Théorique Université Paul Sabatier 118 Route de Narbonne F-31062 Toulouse France CNRS LPT (IRSAMC) F-31062 Toulouse France Department of Mechanical Engineering Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA

We provide a new quantum algorithm that efficiently determines the quality of a least-squares fit over an exponentially large data set by building upon an algorithm for solving systems of linear equations efficiently [Harrow et al., Phys. Rev. Lett. 103, 150502 (2009)]. In many cases, our algorithm can also efficiently find a concise function that approximates the data to be fitted and bound the approximation error. In cases where the input data are pure quantum states, the algorithm can be used to provide an efficient parametric estimation of the quantum state and therefore can be applied as an alternative to full quantum-state tomography given a fault tolerant quantum computer.

关键词： LEAST squares LINEAR algebras APPROXIMATION error PARAMETER estimation COMPUTER algorithms

来源：评论

学校读者我要写书评

暂无评论

Adiabatic quantum Algorithm for Search Engine Ranking

引用

Physical Review Letters 2012年第23期108卷 230506-230506页

作者： Silvano Garnerone Paolo Zanardi Daniel A. Lidar Institute for Quantum Computing University of Waterloo Waterloo ON N2L 3G1 Canada Department of Physics & Astronomy University of Southern California Los Angeles California 90089 USA Center for Quantum Information Science & Technology University of Southern California Los Angeles California 90089 USA Department of Electrical Engineering University of Southern California Los Angeles California 90089 USA Department of Chemistry University of Southern California Los Angeles California 90089 USA

We propose an adiabatic quantum algorithm for generating a quantum pure state encoding of the PageRank vector, the most widely used tool in ranking the relative importance of internet pages. We present extensive numerical simulations which provide evidence that this algorithm can prepare the quantum PageRank state in a time which, on average, scales polylogarithmically in the number of web pages. We argue that the main topological feature of the underlying web graph allowing for such a scaling is the out-degree distribution. The top-ranked log (n) entries of the quantum PageRank state can then be estimated with a polynomial quantum speed-up. Moreover, the quantum PageRank state can be used in “q-sampling” protocols for testing properties of distributions, which require exponentially fewer measurements than all classical schemes designed for the same task. This can be used to decide whether to run a classical update of the PageRank.

关键词： ADIABATIC flow SEARCH engines quantum theory COMPUTER simulation COMPUTER algorithms quantum information science quantum measurement

来源：评论

学校读者我要写书评

暂无评论

Driven Dynamics and Rotary Echo of a Qubit Tunably Coupled to a Harmonic Oscillator

引用

Physical Review Letters 2012年第17期108卷 170503-170503页

作者： S. Gustavsson J. Bylander F. Yan P. Forn-Díaz V. Bolkhovsky D. Braje G. Fitch K. Harrabi D. Lennon J. Miloshi P. Murphy R. Slattery S. Spector B. Turek T. Weir P. B. Welander F. Yoshihara D. G. Cory Y. Nakamura T. P. Orlando W. D. Oliver Research Laboratory of Electronics Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA Department of Nuclear Science and Engineering MIT Cambridge Massachusetts 02139 USA MIT Lincoln Laboratory 244 Wood Street Lexington Massachusetts 02420 USA The Institute of Physical and Chemical Research (RIKEN) Wako Saitama 351-0198 Japan Institute for Quantum Computing and Department of Chemistry University of Waterloo Ontario Canada The Perimeter Institute for Theoretical Physics Ontario Canada Green Innovation Research Laboratories NEC Corporation Tsukuba Ibaraki 305-8501 Japan

We have investigated the driven dynamics of a superconducting flux qubit that is tunably coupled to a microwave resonator. We find that the qubit experiences an oscillating field mediated by off-resonant driving of the resonator, leading to strong modifications of the qubit Rabi frequency. This opens an additional noise channel, and we find that low-frequency noise in the coupling parameter causes a reduction of the coherence time during driven evolution. The noise can be mitigated with the rotary-echo pulse sequence, which, for driven systems, is analogous to the Hahn-echo sequence.

关键词： HARMONIC oscillators SUPERCONDUCTORS QUBITS MICROWAVES RESONATORS quantum theory COHERENCE (Optics)

来源：评论

学校读者我要写书评

暂无评论

No-go theorem for one-way quantum computing on naturally occurring two-level systems

引用

Physical Review A 2011年第5期83卷 050301(R)-050301(R)页

作者： Jianxin Chen Xie Chen Runyao Duan Zhengfeng Ji Bei Zeng Department of Computer Science and Technology Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing China Department of Physics Massachusetts Institute of Technology Cambridge Massachusetts USA Centre for Quantum Computation and Intelligent Systems (QCIS) Faculty of Engineering and Information Technology University of Technology Sydney New South Wales Australia Perimeter Institute for Theoretical Physics Waterloo Ontario Canada State Key Laboratory of Computer Science Institute of Software Chinese Academy of Sciences Beijing China Institute for Quantum Computing and Department of Combinatorics and Optimization University of Waterloo Waterloo Ontario Canada

The ground states of some many-body quantum systems can serve as resource states for the one-way quantum computing model, achieving the full power of quantum computation. Such resource states are found, for example, in spin-52 and spin-32 systems. It is, of course, desirable to have a natural resource state in a spin-12, that is, qubit system. Here, we give a negative answer to this question for frustration-free systems with two-body interactions. In fact, it is shown to be impossible for any genuinely entangled qubit state to be a nondegenerate ground state of any two-body frustration-free Hamiltonian. What is more, we also prove that every spin-12 frustration-free Hamiltonian with two-body interaction always has a ground state that is a product of single- or two-qubit states. In other words, there cannot be any interesting entanglement features in the ground state of such a qubit Hamiltonian.

关键词： quantum computers quantum theory HAMILTONIAN operator HAMILTONIAN systems PHYSICS

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：