Density Waves In Solids

Density Waves In Solids

Author: George Gruner

Publisher: CRC Press

Published: 2018-03-08

Total Pages: 288

ISBN-13: 0429969562

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?Density Waves in Solids is written for graduate students and scientists interested in solid-state sciences. It discusses the theoretical and experimental state of affairs of two novel types of broken symmetry ground states of metals, charge, and spin density waves. These states arise as the consequence of electron-phonon and electron-electron interactions in low-dimensional metals.Some fundamental aspects of the one-dimensional electron gas, and of the materials with anisotropic properties, are discussed first. This is followed by the mean field theory of the phases transitions?discussed using second quantized formalism?together with the various experimental observations on the transition and on the ground states. Fluctuation effects and the collective excitations are reviewed next, using the Ginzburg-Landau formalism, followed by the review of the interaction of these states with the underlying lattice and with impurities. The final chapters are devoted to the response of the ground states to external perturbations.


Diffuse Scattering of X-Rays and Neutrons by Fluctuations

Diffuse Scattering of X-Rays and Neutrons by Fluctuations

Author: Mikhail A. Krivoglaz

Publisher: Springer

Published: 2011-12-16

Total Pages: 284

ISBN-13: 9783642787676

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Mikhail Alexandrovich Krivoglaz died unexpectedly when he was preparing the English edition of his two-volume monograph on diffraction and diffuse scattering of X-rays and neutrons in imperfect crystals. His death was a heavy blow to all who knew him, who had worked with him and to the world science community as a whole. The application of the diffraction techniques for the study of imperfections of crystal structures was the major field of Krivoglaz' work throughout his career in science. He started working in the field in the mid-fifties and since then made fundamental contributions to the theory of real crystals. His results have largely determined the current level of knowledge in this field for more than thirty years. Until the very last days of his life, Krivoglaz continued active studies in the physics of diffraction effects in real crystals. His interest in the theory aided in the explanation of the rapidly advancing experimental studies. The milestones marking important stages of his work were the first monograph on the theory of X-ray and neutron scattering in real crystals which was published in Russian in 1967 (a revised English edition in 1969), and the two-volume mono graph published in Russian in 1983-84 (this edition is the revised translation of the latter).


Emergent States in Photoinduced Charge-Density-Wave Transitions

Emergent States in Photoinduced Charge-Density-Wave Transitions

Author: Alfred Zong

Publisher: Springer Nature

Published: 2021-09-17

Total Pages: 234

ISBN-13: 3030817512

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This book advances understanding of light-induced phase transitions and nonequilibrium orders that occur in a broken-symmetry system. Upon excitation with an intense laser pulse, materials can undergo a nonthermal transition through pathways different from those in equilibrium. The mechanism underlying these photoinduced phase transitions has long been researched, but many details in this ultrafast, non-adiabatic regime still remain to be clarified. The work in this book reveals new insights into this phenomena via investigation of photoinduced melting and recovery of charge density waves (CDWs). Using several time-resolved diffraction and spectroscopic techniques, the author shows that the light-induced melting of a CDW is characterized by dynamical slowing-down, while the restoration of the symmetry-breaking order features two distinct timescales: A fast recovery of the CDW amplitude is followed by a slower re-establishment of phase coherence, the latter of which is dictated by the presence of topological defects in the CDW. Furthermore, after the suppression of the original CDW by photoexcitation, a different, competing CDW transiently emerges, illustrating how a hidden order in equilibrium can be unleashed by a laser pulse. These insights into CDW systems may be carried over to other broken-symmetry states, such as superconductivity and magnetic ordering, bringing us one step closer towards manipulating phases of matter using a laser pulse.


Interacting Electrons and Quantum Magnetism

Interacting Electrons and Quantum Magnetism

Author: Assa Auerbach

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 249

ISBN-13: 1461208696

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In the excitement and rapid pace of developments, writing pedagogical texts has low priority for most researchers. However, in transforming my lecture l notes into this book, I found a personal benefit: the organization of what I understand in a (hopefully simple) logical sequence. Very little in this text is my original contribution. Most of the knowledge was collected from the research literature. Some was acquired by conversations with colleagues; a kind of physics oral tradition passed between disciples of a similar faith. For many years, diagramatic perturbation theory has been the major theoretical tool for treating interactions in metals, semiconductors, itiner ant magnets, and superconductors. It is in essence a weak coupling expan sion about free quasiparticles. Many experimental discoveries during the last decade, including heavy fermions, fractional quantum Hall effect, high temperature superconductivity, and quantum spin chains, are not readily accessible from the weak coupling point of view. Therefore, recent years have seen vigorous development of alternative, nonperturbative tools for handling strong electron-electron interactions. I concentrate on two basic paradigms of strongly interacting (or con strained) quantum systems: the Hubbard model and the Heisenberg model. These models are vehicles for fundamental concepts, such as effective Ha miltonians, variational ground states, spontaneous symmetry breaking, and quantum disorder. In addition, they are used as test grounds for various nonperturbative approximation schemes that have found applications in diverse areas of theoretical physics.


Two Dimensional Transition Metal Dichalcogenides

Two Dimensional Transition Metal Dichalcogenides

Author: Narayanasamy Sabari Arul

Publisher: Springer

Published: 2019-07-30

Total Pages: 361

ISBN-13: 9811390452

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This book presents advanced synthesis techniques adopted to fabricate two-dimensional (2D) transition metal dichalcogenides (TMDs) materials with its enhanced properties towards their utilization in various applications such as, energy storage devices, photovoltaics, electrocatalysis, electronic devices, photocatalysts, sensing and biomedical applications. It provides detailed coverage on everything from the synthesis and properties to the applications and future prospects of research in 2D TMD nanomaterials.


Planewaves, Pseudopotentials and the LAPW Method

Planewaves, Pseudopotentials and the LAPW Method

Author: David J. Singh

Publisher: Springer Science & Business Media

Published: 2013-06-29

Total Pages: 121

ISBN-13: 1475723121

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Over the past decade the world's technological and industrial base has become increasingly dependent on advanced materials. There is every indication that this trend will accelerate and that progress in many areas will increasingly depend on the development of new materials and processing techniques. A second and equally significant trend is the continuing ascent of the information technologies, which now touch almost every aspect of life in some way. In this environment it is natural that there is a strong interest in using numerical modeling in materials science. With its extreme accuracy and reasonable computational efficiency, the linearized augmented plane wave (LAPW) method has emerged as the standard by which density functional calculations for transition metal and rare-earth containing materials are judged. Planewaves, Pseudopotentials and the LAPW Method presents a thorough and self-contained exposition of the LAPW method, making this powerful technique more accessible to researchers and students who have some familiarity with local density approximation calculations. Theory is discussed, but the emphasis is on how practical implementation proceeds. In addition, the author suggests future directions for adapting the LAPW method to simulations of complex materials requiring large unit cells. He does this by elucidating the connections between the LAPW method and planewave pseudopotential approaches and by showing how Car--Parrinello type algorithms can be adapted to the LAPW method. Planewaves, Pseudopotentials and the LAPW Method is a valuable resource for researchers already involved in electronic structure calculations, as well as for newcomers seeking quick mastery of the LAPW technique.


Quantum Confined Excitons in 2-Dimensional Materials

Quantum Confined Excitons in 2-Dimensional Materials

Author: Carmen Palacios-Berraquero

Publisher: Springer

Published: 2018-11-02

Total Pages: 125

ISBN-13: 3030014827

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This book presents the first established experimental results of an emergent field: 2-dimensional materials as platforms for quantum technologies, specifically through the optics of quantum-confined excitons. It also provides an extensive review of the literature from a number of disciplines that informed the research, and introduces the materials of focus – 2d Transition Metal Dichalcogenides (2d-TMDs) – in detail, discussing electronic and chemical structure, excitonic behaviour and response to strain. This is followed by a brief overview of quantum information technologies, including concepts such as single-photon sources and quantum networks. The methods chapter addresses quantum optics techniques and 2d-material processing, while the results section shows the development of a method to deterministically create quantum dots (QDs) in the 2d-TMDs, which can trap single-excitons; the fabrication of atomically thin quantum light-emitting diodes to induce all-electrical single-photon emission from the QDs, and lastly, the use of devices to controllably trap single-spins in the QDs –the first step towards their use as optically-addressable matter qubits.


Two-Dimensional Transition-Metal Dichalcogenides

Two-Dimensional Transition-Metal Dichalcogenides

Author: Alexander V. Kolobov

Publisher: Springer

Published: 2016-07-26

Total Pages: 545

ISBN-13: 3319314505

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This book summarizes the current status of theoretical and experimental progress in 2 dimensional graphene-like monolayers and few-layers of transition metal dichalcogenides (TMDCs). Semiconducting monolayer TMDCs, due to the presence of a direct gap, significantly extend the potential of low-dimensional nanomaterials for applications in nanoelectronics and nano-optoelectronics as well as flexible nano-electronics with unprecedented possibilities to control the gap by external stimuli. Strong quantum confinement results in extremely high exciton binding energies which forms an interesting platform for both fundamental studies and device applications. Breaking of spatial inversion symmetry in monolayers results in strong spin-valley coupling potentially leading to their use in valleytronics. Starting with the basic chemistry of transition metals, the reader is introduced to the rich field of transition metal dichalcogenides. After a chapter on three dimensional crystals and a description of top-down and bottom-up fabrication methods of few-layer and single layer structures, the fascinating world of two-dimensional TMDCs structures is presented with their unique atomic, electronic, and magnetic properties. The book covers in detail particular features associated with decreased dimensionality such as stability and phase-transitions in monolayers, the appearance of a direct gap, large binding energy of 2D excitons and trions and their dynamics, Raman scattering associated with decreased dimensionality, extraordinarily strong light-matter interaction, layer-dependent photoluminescence properties, new physics associated with the destruction of the spatial inversion symmetry of the bulk phase, spin-orbit and spin-valley couplings. The book concludes with chapters on engineered heterostructures and device applications such as a monolayer MoS2 transistor. Considering the explosive interest in physics and applications of two-dimensional materials, this book is a valuable source of information for material scientists and engineers working in the field as well as for the graduate students majoring in materials science.


Crystallography and Crystal Chemistry of Materials with Layered Structures

Crystallography and Crystal Chemistry of Materials with Layered Structures

Author: F.A. Lévy

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 374

ISBN-13: 9401014337

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In the last ten years, the chemistry and physics of materials with layered structures became an intensively investigated field in the study of the solid state. Research into physical properties of these crystals and especially investigations of their physical anisotropy related to the structural anisotropy has led to remarkable and perplexing results. Most of the layered materials exist in several polytypic modifications and can include stacking faults. The crystal structures are therefore complex and it became apparent that there was a great need for a review of the crystallographic data of materials approximating two-dimensional solids. This second volume in the series 'Physics and Chemistry of Materials with Layered Structures' has been written by specialists of different classes of layered materials. Structural data are reviewed and the most important relations between the structure and the chemical and physical properties are emphasized. The first three contributions are devoted to the transition metal dichalcogenides whose physical properties have been investigated in detail. The crystallographic data and crystal growth conditions are presented in the first paper. The second paper constitutes an incisive review of the phase transformations and charge density waves which have been observed in the metallic dichalcogenides. In two contributions the layered structures of newer ternary compounds are de scribed and the connection between structure and non-stoichiometry is discussed.


Ultrafast Photonics

Ultrafast Photonics

Author: A. Miller

Publisher: CRC Press

Published: 2019-08-22

Total Pages: 328

ISBN-13: 0429524935

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Ultrafast photonics has become an interdisciplinary topic of high international research interest because of the spectacular development of compact and efficient lasers producing optical pulses with durations in the femtosecond time domain. Present day long-haul telecommunications systems are almost entirely based on the transmission of short burst