Advances in Physics最新文献_第10页

Decoherence in solid-state qubits 固态量子比特的退相干

1区物理与天体物理

Advances in Physics Pub Date : 2008-05-01 DOI: 10.1080/00018730802218067

L. Chirolli, G. Burkard

{"title":"Decoherence in solid-state qubits","authors":"L. Chirolli, G. Burkard","doi":"10.1080/00018730802218067","DOIUrl":"https://doi.org/10.1080/00018730802218067","url":null,"abstract":"The interaction of solid-state qubits with environmental degrees of freedom strongly affects the qubit dynamics, and leads to decoherence. In quantum information processing with solid-state qubits, decoherence significantly limits the performances of such devices. Therefore, it is necessary to fully understand the mechanisms that lead to decoherence. In this review, we discuss how decoherence affects two of the most successful realizations of solid-state qubits, namely, spin qubits and superconducting qubits. In the former, the qubit is encoded in the spin 1/2 of the electron, and it is implemented by confining the electron spin in a semiconductor quantum dot. Superconducting devices show quantum behaviour at low temperatures, and the qubit is encoded in the two lowest energy levels of a superconducting circuit. The electron spin in a quantum dot has two main decoherence channels, a (Markovian) phonon-assisted relaxation channel, due to the presence of a spin–orbit interaction, and a (non-Markovian) spin bath constituted by the spins of the nuclei in the quantum dot that interact with the electron spin via the hyperfine interaction. In a superconducting qubit, decoherence takes place as a result of fluctuations in the control parameters, such as bias currents, applied flux and bias voltages, and via losses in the dissipative circuit elements.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018730802218067","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58772326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 129

Matrix product states, projected entangled pair states, and variational renormalization group methods for quantum spin systems 量子自旋系统的矩阵积态、投射纠缠对态和变分重整化群方法

1区物理与天体物理

Advances in Physics Pub Date : 2008-03-01 DOI: 10.1080/14789940801912366

F. Verstraete, V. Murg, J. Cirac

引用次数: 1256

Advances of and by phase-field modelling in condensed-matter physics 凝聚态物理中相场模型的研究进展

1区物理与天体物理

Advances in Physics Pub Date : 2008-01-01 DOI: 10.1080/00018730701822522

H. Emmerich

{"title":"Advances of and by phase-field modelling in condensed-matter physics","authors":"H. Emmerich","doi":"10.1080/00018730701822522","DOIUrl":"https://doi.org/10.1080/00018730701822522","url":null,"abstract":"Phase-field modelling is still a young discipline in condensed-matter physics, which established itself for the class of systems that can be characterised by domains of different phases separated by a distinct interface. Driven out of equilibrium, their dynamics result in the evolution of those interfaces which might develop into well defined-structures with characteristic length scales at the nano-, micro- or meso-scale. Since the material properties of such systems are to a large extent determined by those small-scale structures, acquiring a precise understanding of the mechanisms that drive the interfacial dynamics is a great challenge for scientists in this field. Phase-field modelling is an approach that allows this challenge to be tackled in a simulation-based manner. This review provides a critical overview of the conceptual background of the phase-field method, the most relevant fields of condensed-matter physics that have been approached using phase-field modelling, as well as the respective model formulations and the insight gained so far via their simulation and analysis. Moreover, we discuss directions of further development and the quality of the scientific contributions to be expected from those.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018730701822522","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58772283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 206

Universal behaviour and the two-component character of magnetically underdoped cuprate superconductors 磁欠掺杂铜超导体的普遍行为和双组分特性

1区物理与天体物理

Advances in Physics Pub Date : 2008-01-01 DOI: 10.1080/00018730802567505

V. Barzykin, D. Pines

{"title":"Universal behaviour and the two-component character of magnetically underdoped cuprate superconductors","authors":"V. Barzykin, D. Pines","doi":"10.1080/00018730802567505","DOIUrl":"https://doi.org/10.1080/00018730802567505","url":null,"abstract":"We present a detailed review of scaling behaviour in the magnetically underdoped cuprate superconductors (hole dopings less than 0.20) and show that it reflects the presence of two coupled components throughout this doping regime: a non-Landau Fermi liquid and a spin liquid whose behaviour maps onto the theoretical Monte Carlo calculations of the two-dimensional Heisenberg model of localized Cu spins for most of its temperature domain. We use this mapping to extract the doping dependence of the strength, f(x) of the spin liquid component and the effective interaction, J eff(x) between the remnant localized spins that compose it; we find that both decrease linearly with x as the doping level increases. We discuss the physical origin of pseudogap behaviour and conclude that it is consistent with scenarios in which the both the large energy gaps found in the normal state and their subsequent superconductivity are brought about by the coupling between the Fermi liquid quasiparticles and the spin liquid excitations, and that differences in this coupling between the 1–2–3 and 2–1–4 materials can explain the measured differences in their superconducting transition temperatures and other properties.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018730802567505","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58772448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 30

Analyzing and modeling real-world phenomena with complex networks: a survey of applications 用复杂网络分析和建模现实世界现象:应用综述

1区物理与天体物理

Advances in Physics Pub Date : 2007-11-20 DOI: 10.1080/00018732.2011.572452

L. D. Costa, O. N. Oliveira, G. Travieso, F. Rodrigues, P. R. Villas Boas, L. Antiqueira, M. Viana, Luis Enrique Correa Rocha

引用次数: 692

A dynamical systems approach to mixing and segregation of granular materials in tumblers 一个动态系统方法的混合和分离颗粒材料在玻璃杯

1区物理与天体物理

Advances in Physics Pub Date : 2007-09-01 DOI: 10.1080/00018730701611677

S. W. Meier, Richard M. Lueptow, J. Ottino

{"title":"A dynamical systems approach to mixing and segregation of granular materials in tumblers","authors":"S. W. Meier, Richard M. Lueptow, J. Ottino","doi":"10.1080/00018730701611677","DOIUrl":"https://doi.org/10.1080/00018730701611677","url":null,"abstract":"The physics of granular matter is one of the big questions in science. Granular matter serves as a prototype of collective systems far from equilibrium and fundamental questions remain. At the same time, an understanding of granular matter has tremendous practical importance. Among practical problems, granular mixing and its interplay with segregation is arguably at the top of the list in terms of impact. Granular mixing in three-dimensional systems is complicated, as flow induces segregation by particle size or density. Several approaches and points of view for analysis are possible in principle, ranging from continuum to discrete. Flow and segregation in three-dimensional systems is seemingly complicated; however, to a reasonable approximation, all of the dynamics takes place in a thin flowing surface layer. This observation, coupled with key experimental results, leads to a simple, compact and extensible continuum-based dynamical systems framework applicable to time-periodic flow in quasi-two-dimensional tumblers and three-dimensional systems (such as spheres and cubes) rotated about one or more axes of rotation. The case of time-periodic systems, in its simplest version, can be viewed as a mapping of a domain into itself. The placement of periodic points can be investigated using symmetry concepts; the character of the periodic points and associated manifolds provides a skeleton for the flow and a template for segregation processes occurring in the flow.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018730701611677","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58771849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 140

On the Ising model for the simple cubic lattice 关于简单立方晶格的Ising模型

1区物理与天体物理

Advances in Physics Pub Date : 2007-09-01 DOI: 10.1080/00018730701577548

R. Häggkvist, A. Rosengren, P. Lundow, K. Markström, Daniel Andrén, P. Kundrotas

{"title":"On the Ising model for the simple cubic lattice","authors":"R. Häggkvist, A. Rosengren, P. Lundow, K. Markström, Daniel Andrén, P. Kundrotas","doi":"10.1080/00018730701577548","DOIUrl":"https://doi.org/10.1080/00018730701577548","url":null,"abstract":"The Ising model was introduced in 1920 to describe a uniaxial system of magnetic moments, localized on a lattice, interacting via nearest-neighbour exchange interaction. It is the generic model for a continuous phase transition and arguably the most studied model in theoretical physics. Since it was solved for a two-dimensional lattice by Onsager in 1944, thereby representing one of the very few exactly solvable models in dimensions higher than one, it has served as a testing ground for new developments in analytic treatment and numerical algorithms. Only series expansions and numerical approaches, such as Monte Carlo simulations, are available in three dimensions. This review focuses on Monte Carlo simulation. We build upon a data set of unprecedented size. A great number of quantities of the model are estimated near the critical coupling. We present both a conventional analysis and an analysis in terms of a Puiseux series for the critical exponents. The former gives distinct values of the high- and low-temperature exponents; by means of the latter we can get these exponents to be equal at the cost of having true asymptotic behaviour being found only extremely close to the critical point. The consequences of this for simulations of lattice systems are discussed at length.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018730701577548","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58771843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 30

Fluctuation scaling in complex systems: Taylor's law and beyond 复杂系统中的波动缩放:泰勒定律及以后

1区物理与天体物理

Advances in Physics Pub Date : 2007-08-15 DOI: 10.1080/00018730801893043

Z. Eisler, I. Bartos, J. Kertész

{"title":"Fluctuation scaling in complex systems: Taylor's law and beyond","authors":"Z. Eisler, I. Bartos, J. Kertész","doi":"10.1080/00018730801893043","DOIUrl":"https://doi.org/10.1080/00018730801893043","url":null,"abstract":"Complex systems consist of many interacting elements which participate in some dynamical process. The activity of various elements is often different and the fluctuation in the activity of an element grows monotonically with the average activity. This relationship is often of the form ‘fluctuations ≈ constant × averageα’, where the exponent α is predominantly in the range [1/2, 1]. This power law has been observed in a very wide range of disciplines, ranging from population dynamics through the Internet to the stock market and it is often treated under the names Taylor's law or fluctuation scaling. This review attempts to show how general the above scaling relationship is by surveying the literature, as well as by reporting some new empirical data and model calculations. We also show some basic principles that can underlie the generality of the phenomenon. This is followed by a mean-field framework based on sums of random variables. In this context the emergence of fluctuation scaling is equivalent to some corresponding limit theorems. In certain physical systems fluctuation scaling can be related to finite size scaling. 1Dedicated to the memory of L. R. Taylor (1924–2007).","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018730801893043","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58772296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 274

Gutzwiller–RVB theory of high-temperature superconductivity: Results from renormalized mean-field theory and variational Monte Carlo calculations 高温超导的Gutzwiller-RVB理论:重整化平均场理论和变分蒙特卡罗计算的结果

1区物理与天体物理

Advances in Physics Pub Date : 2007-07-06 DOI: 10.1080/00018730701627707

B. Edegger, V. N. Muthukumar, C. Gros

引用次数: 133

Triplet versus singlet superconductivity in quasi-one-dimensional conductors 准一维导体中的三重态与单线态超导

1区物理与天体物理

Advances in Physics Pub Date : 2007-06-01 DOI: 10.1080/00018730701403190

Wei Zhang, C. A. R. Sá de Melo

{"title":"Triplet versus singlet superconductivity in quasi-one-dimensional conductors","authors":"Wei Zhang, C. A. R. Sá de Melo","doi":"10.1080/00018730701403190","DOIUrl":"https://doi.org/10.1080/00018730701403190","url":null,"abstract":"Quasi-one-dimensional organic conductors are highly unconventional materials, which exhibit a wide variety of phenomena, including spin density waves, quantum Hall effect, and superconductivity. In this paper, we review some experimental and theoretical developments concerning the superconducting state of these systems, where a particular emphasis is placed on the possibility of triplet superconductivity. This possibility is supported by various experiments including upper critical field, Knight shift and NMR relaxation time measurements on the Bechgaard salt bistetramethyltetraselenafulvalene hexafluorophosphate [(TMTSF)2PF6]. However, similar NMR results are still lacking for another compound (TMTSF)2ClO4 and other members of the Bechgaard salts family. Furthermore, the pairing mechanism and order parameter symmetry are not yet fully known. Therefore, we include a discussion of both triplet and singlet pairing states, and analyse briefly the possibility that the symmetries of the superconducting order parameters are different for various compounds. Finally, we also discuss some open questions regarding the superconducting state of these systems.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018730701403190","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58771833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13