The theory of superconductivity in the high-Tc curprates

Recently we have shown that an anistropic Anderson-Morel state may be stabilized by feedback effects in the effective interaction arising from introduction of a gap in the spin-fluctuation spectrum.Показать полностьюRecently we have shown that an anistropic Anderson-Morel state may be stabilized by feedback effects in the effective interaction arising from introduction of a gap in the spin-fluctuation spectrum. In this paper we determine the general form of the fourth-order term in the free energy owing to the above mechanism and use this result to make predictions regarding the phase diagram in the presence of a magnetic field and as a function of pressure.

propertiesof a Two-dimensional Electron gas, energy levels and Wave Functions.

This book presents the idea of zero-range potentials and shows the limitations of the point models used in structural mechanics. It also offers specific examples from the theory of generalized functions, regularization of super-singular integral equations and other specifics of the boundary value problems for partial differential operators of the fourth order.

In the last two decades remarkable progress has been made in understanding and describing tunneling processes in complex systems in terms of classical trajectories.Показать полностьюIn the last two decades remarkable progress has been made in understanding and describing tunneling processes in complex systems in terms of classical trajectories. This book introduces recent concepts and achievements with particular emphasis on a dynamical formulation and relations to specific systems in mesoscopic, molecular, atomic and nuclear physics. Advanced imaginary time techniques, e.g. for decay rates and tunnel splittings, are discussed in the first part. The second part covers current developments for wave-packet tunneling in real-time, and the third part describes thermodynamical and nonequilibrium approaches for barrier transmission in dissipative systems.

The aim of this book is to review recent achievements in the theoretical investigations of the electronic structure, optical, magneto-optical (MO), and x-ray magnetic circular dichroism (XMCD) properties of compounds and Multilayered structures.Показать полностьюThe aim of this book is to review recent achievements in the theoretical investigations of the electronic structure, optical, magneto-optical (MO), and x-ray magnetic circular dichroism (XMCD) properties of compounds and Multilayered structures. Chapter 1 of this book is of an introductory character and presents the theoretical foundations of the band theory of solids such as the density functional theory for ground state properties of solids including local density approximation (LDA). It also presents some modifications to the LDA, such as gradient correction, self-interaction correction, LDA+U method, orbital polarization correction, GW approximation, and dynamical mean-field theory. The description of the magneto-optical effects and linear response theory are also presented. The book describes the MO properties for a number of 3d materials, such as elemental ferromagnetic metals (Fe, Co and Ni) and paramagnetic metals in external magnetic fields (Pd and Pt), some important 3d compounds such as XPt3 (X=V, Cr, Mn, Fe and Co), Heusler alloys, chromium spinel chalcogenides, MnB and strongly correlated magnetite Fe304. It also describes the recent achievements in both the experimental and theoretical investigations of the electronic structure, optical and MO properties of transition metal multilayered structures (MLS). The book also presents the MO properties of f band ferromagnetic materials: Tm, Nd, Sm, Ce and La monochalcogenides, some important Yb compounds, SmB6 and Nd3S4, UFe2, U3X4 (X=P, As, Sb, Bi, Se and Te), UCu2P2, UCuP2, UCuAs2, UAsSe, URhA1, UGa2 and UPd3. Within the total group of alloys and compounds, we discuss their MO spectra in relationship to: the spin-orbit coupling strength, the magnitude of the local magnetic moment, the degree of hybridization in the bonding, the half-metallic character, or, equivalently, the Fermi level filling of the bandstructure, the intraband plasma frequency, and the influence of the crystal structure. In the last chapter results of recent theoretical investigations on the MXCD in various representative transition metal 4f and 5f systems are presented.

The aim of this book is to review recent achievements in the theoretical investigations of the electronic structure, optical, magneto-optical (MO), and x-ray magnetic circular dichroism (XMCD) properties of compounds and Multilayered structures. Chapter 1 of this book is of an introductory character and presents the theoretical foundations of the band theory of solids such as the density functional theory for ground state properties of solids including local density approximation (LDA).Показать полностьюThe aim of this book is to review recent achievements in the theoretical investigations of the electronic structure, optical, magneto-optical (MO), and x-ray magnetic circular dichroism (XMCD) properties of compounds and Multilayered structures. Chapter 1 of this book is of an introductory character and presents the theoretical foundations of the band theory of solids such as the density functional theory for ground state properties of solids including local density approximation (LDA). It also presents some modifications to the LDA, such as gradient correction, self-interaction correction, LDA+U method, orbital polarization correction, GW approximation, and dynamical mean-field theory. The description of the magneto-optical effects and linear response theory are also presented. The book describes the MO properties for a number of 3d materials, such as elemental ferromagnetic metals (Fe, Co and Ni) and paramagnetic metals in external magnetic fields (Pd and Pt), some important 3d compounds such as XPt3 (X=V, Cr, Mn, Fe and Co), Heusler alloys, chromium spinel chalcogenides, MnB and strongly correlated magnetite Fe304. It also describes the recent achievements in both the experimental and theoretical investigations of the electronic structure, optical and MO properties of transition metal multilayered structures (MLS). The book also presents the MO properties of f band ferromagnetic materials: Tm, Nd, Sm, Ce and La monochalcogenides, some important Yb compounds, SmB6 and Nd3S4, UFe2, U3X4 (X=P, As, Sb, Bi, Se and Te), UCu2P2, UCuP2, UCuAs2, UAsSe, URhA1, UGa2 and UPd3. Within the total group of alloys and compounds, we discuss their MO spectra in relationship to: the spin-orbit coupling strength, the magnitude of the local magnetic moment, the degree of hybridization in the bonding, the half-metallic character, or, equivalently, the Fermi level filling of the bandstructure, the intraband plasma frequency, and the influence of the crystal structure. In the last chapter results of recent theoretical investig

Describes chaotic behaviors mainly associated with nonlinear carrier transport via the impact-ionization avalanche in bulk-semiconductor materials, including bifurcation routes to chaos, fractal dimensions of strange attractors, and circle map behavior

The drude theory of metals, The summerfeld theory of metals, Failures of the free electron model.

This is a textbook on quantum magnetism and on modern techniques in strongly correlated electron systems. It explains concepts and techniques that are useful in widely diverse areas such as quantum spin systems, the fractional quantum Hall effect, superfluidity, and high-temperature superconductivity.Показать полностьюThis is a textbook on quantum magnetism and on modern techniques in strongly correlated electron systems. It explains concepts and techniques that are useful in widely diverse areas such as quantum spin systems, the fractional quantum Hall effect, superfluidity, and high-temperature superconductivity. The book starts with interactions between electrons and spin exchange; the Heisenberg and t-J models are derived from the Hubbard model, and itinerant magnetism is presented as a variational theory. Superconductivity and charge ordering in the negative-U Hubbard model are described by pseudospins. The Heisenberg model is used to elucidate general concepts such as spontaneous symmetry breaking, Goldstone modes and spin waves, thermal and quantum disorder in low dimensions, Haldane’s gap. The text emphasizes nonperturbative approaches: ground state theorems, variational wavefunctions, parent Hamiltonians, single mode excitations, the spin path integral and its large-S expansion, Haldane’s mapping, Polyakov’s weak-coupling renormalization, large-N expansions for constrained systems, and the semiclassical theory of the t-J model. Mathematical derivations are self contained. Appendices provide standard many-body tools including second quantization, Grassmann variables, generating functionals, linear response, correlation functions, Fermi and Bose coherent-states path integrals, Matsubara representation, and the method of steepest descents. There are guided bibliographies and exercises at the end of chapters.

X-ray and neutron dynamical diffraction.

The adiabatic quantum transport in multiply connected systems is examined. The systems considered have several holes, usually three or more, threaded by independent flux tubes, the transport properties of which are described by matrix-valued functions of the fluxes.Показать полностьюThe adiabatic quantum transport in multiply connected systems is examined. The systems considered have several holes, usually three or more, threaded by independent flux tubes, the transport properties of which are described by matrix-valued functions of the fluxes. The main theme is the differential-geometric interpretation of Kubo’s formulas as curvatures. Because of this interpretation, and because flux space can be identified with the multitorus, the adiabatic conductances have topological significance, related to the first Chern character. In particular, they have quantized averages. The authors describe various classes of quantum Hamiltonians that describe multiply connected systems and investigate their basic properties. They concentrate on models that reduce to the study of finite-dimensional matrices. In particular, the reduction of the "free-electron" Schrodinger operator, on a network of thin wires, to a matrix problem is described in detail. The authors define “loop currents” and investigate their properties and their dependence on the choice of flux tubes. They introduce a method of topological classification of networks according to their transport. This leads to the analysis of level crossings and to the association of “charges” with crossing points. Networks made with three equilateral triangles are investigated and classified, both numerically and analytically. Many of these networks turn out to have nontrivial topological transport properties for both the free-electron and the tight-binding models. The authors conclude with some open problems and questions.

When electrons pass through a cylindrical electrical conductor aligned in a magnetic field, their wave-like nature manifests itself as a periodic oscillation in the electrical resistance as a function of the enclosed magnetic flux.Показать полностьюWhen electrons pass through a cylindrical electrical conductor aligned in a magnetic field, their wave-like nature manifests itself as a periodic oscillation in the electrical resistance as a function of the enclosed magnetic flux. This phenomenon reflects the dependence of the phase of the electron wave on the magnetic field, known as the Aharonov-Bohm effect, which causes a phase difference, and hence interference, between partial waves encircling the conductor in opposite directions. Such oscillations have been observed in micrometre-sized thin-walled metallic cylinders and lithographically fabricated rings. Carbon nanotubes are composed of individual graphene sheets rolled into seamless hollow cylinders with diameters ranging from 1nm to about 20nm. They are able to act as conducting molecular wires, making them ideally suited for the investigation of quantum interference at the single-molecule level caused by the Aharonov-Bohm effect. Here we report magnetoresistance measurements on individual multi-walled nanotubes, which display pronounced resistance oscillations as a function of magnetic flux.We find that the oscillations are in good agreement with theoretical predictions for the Aharonov-Bohm effect in a hollow conductor with a diameter equal to that of the outermost shell of the nanotubes. In some nanotubes we also observe shorter-period oscillations, which might result from anisotropic electron currents caused by defects in the nanotube lattice.

Multilinear Mappings, Definition of Tensors over Euclidean Vector Spaces, Alternating Tensors, Determinants, Orientation, and n-dimensional Right-handedness , Tensor Products, Polyad Bases and Tensor Components, The Lifting Theorem, Generalized Dot Products,How to Rotate Tensors (and why), Differential Calculus of Tensors, Integral Identities, Eulerian and Lagrangian Descriptions of a Continuum, Conservation Laws in a Continuum, Strain and Deformation, Constitutive Relations.

Magnetism is a somewhat peculiar research field. It clearly has a quantum-mechanical basis – the microsopic exchange interactions arise entirely from the exclusion principle, in conjunction with respulsive interactions between electrons.Показать полностьюMagnetism is a somewhat peculiar research field. It clearly has a quantum-mechanical basis – the microsopic exchange interactions arise entirely from the exclusion principle, in conjunction with respulsive interactions between electrons. And yet until recently the vast majority of magnetism researchers and users of magnetic phenomena around the world paid no attention to these quantum-mechanical roots. Thus, eg., the huge ($400 billion per annum) industry which manufactures hard discs, and other components in the information technology sector, depends entirely on room-temperature properties of magnets — yet at the macroscopic or mesoscopic scales of interest to this industry, room-temperature magnets behave entirely classically. This situation has now begun to change, and the quantum collective properties of magnetic systems, for so long of interest only to a few, have begun to move to centre stage. There are several reasons for this. One is the increasing use of low temperatures in industrial and applied research labs, and the recognition that the low-T properties of many new magnetic materials are of great potential use in future devices. Another is the emergence of nanoscience, and its offshoot nanotechnology, as an important new discipline – the majority of high-tech applications of nanotechnology so far envisaged will also be low-temperature ones. All this has meant that collective quantum phenomena, occurring at low T in quantum dots, magnetic molecules, and nanoscopic conductors, have suddenly become interesting to more than just pure physics researchers. The design of new magnetic quantum materials, of spin-based quantum devices in low-dimensional geometries, and quantum nanomagnetic systems, using either physical or chemical techniques, has now become the concern of many applied physicists and chemists. An interesting by-product of this broader interest in collective quantum spin phenomena has been the increasing focus, by applied physicists and even start-up companies, on some of the more exot

This is a book about laser cooling, a new research field with many potential applications. The authors present an original approach, using the tools and concepts of statistical physics.Показать полностьюThis is a book about laser cooling, a new research field with many potential applications. The authors present an original approach, using the tools and concepts of statistical physics. A new understanding of laser cooling, both intuitive and quantitative, is obtained. The volume also comprises a case study allowing non-Gaussian (Levy) statistics, a technique being used more frequently in many different fields.

This book surveys all aspects of the Josephson effect—from the underlying physical theory to actual and proposed engineering applications. Both ends of this spectrum are interesting.Показать полностьюThis book surveys all aspects of the Josephson effect—from the underlying physical theory to actual and proposed engineering applications. Both ends of this spectrum are interesting. The physical theory is novel and important for many macroscopic quantum effects, which have a rich and yet untapped potential for technical development. We attempt here to present more than a survey and less than an exhaustive exposition of this wide field. Rather than to cover everything, we have tried to uncover those aspects of theory, fabrication technology, and device application that will be of lasting value.

Presenting a unified approach to the liquid state, this book focusses on the concepts and theoretical methods that are necessary for an understanding of the physics and chemistry of the fluid state.Показать полностьюPresenting a unified approach to the liquid state, this book focusses on the concepts and theoretical methods that are necessary for an understanding of the physics and chemistry of the fluid state. The authors do not attempt to cover the whole field in an encyclopedic manner. Instead, important ideas are presented in a concise and rigorous style, and illustrated with examples from both simple molecular liquids and more complex soft condensed matter systems such as polymers, colloids, and liquid crystals. After a general chapter introducing the liquid state, the book is in four parts devoted to: thermodynamics; structure and fluctuations; phase transitions, interfaces and inhomogeneous fluids; and, finally, transport and dynamics. Each chapter introduces a new set of closely related concepts and theoretical methods, which are then illustrated by a number of specific applications covering a broad range of physical situations.

The distortion of iron cristal, the distortion of single cristals of metals, the plastic distortion of metal.

The book starts with a qualitative analysis of the outcome of the two-particle correlation spectroscopy of localized and delocalized electronic systems as they occur in atoms and solids.Показать полностьюThe book starts with a qualitative analysis of the outcome of the two-particle correlation spectroscopy of localized and delocalized electronic systems as they occur in atoms and solids. The second chapter addresses how spin-dependent interactions can be imaged by means of correlation spectroscopy, both in spin-polarized and extended systems. A further chapter discusses possible pathways for the production of interacting two-particle continuum states. After presenting some established ways of quantifying electronic correlations and pointing out the relationship to correlation spectroscopy, the author addresses in a separate chapter the electron-electron interaction in extended systems, and illustrates the ideas by some applications to fullerenes and metal clusters. The last two chapters are devoted to the investigation of the potential of two-particle spectroscopy in studying ordered surfaces and disordered samples.