Download or read book Charge Density Waves in 2D Transition Metal Dichalcogenides written by Anton A. Anikin and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: At low temperatures, the electronic structure of metals becomes unstable, and instabilities often develop correlated electronic states, decreasing the number of free carriers. One of these correlated states is a charge density wave state. It usually arises under the interaction of free carriers with phonons, and it is manifested as a superstructure over the original crystal lattice. The charge density wave state presents distinguishable experimental fingerprints in many physical properties of the crystal, spontaneously breaking its translational symmetry. The physics of the charge density wave is well established in the case of a one-dimensional metal; however, there are lot of open issues, when describing the systems of higher dimensions. The charge density wave state could potentially be utilized in low-energy electronic devices. Transition metal dichalcogenides are quasi two-dimensional materials, that exhibit a correlated electronic behavior, such as the superconductivity and the charge density wave. Due to their simple crystalline structures, nearly perfect crystals can be grown, and the electronic correlations can be studied in the absence of any disorder. An example of this class of materials is 2H-NbSe2, that undergoes both the charge density wave (T_CDW=33.5 K) and superconducting (T_SC=7.2 K) transitions. The first part of this work is focused on the single crystal growth, electronic transport characterization, and results of ultrafast transient reflectivity measurements of 2H-NbSe2 single crystals. Coherent lattice dynamics and characteristic relaxation times of photoexcited charge carriers have been extracted from the broadband transient optical spectroscopy. A wide temporal profile gives opportunity to track multiple ultrafast phenomena within the same experiment from 50 fs to few nanoseconds. The physical mechanisms leading to the charge density wave condensation are being discussed here. The second part of this work is focused on a studying of the temperature hysteresis in electrical transport properties in freshly grown undoped and doped 1T-TiSe2 single crystals. This transition metal dichalcogenide undergoes a chiral charge density wave at low temperatures (T_CDW=202 K). An irreversible behavior of electrical properties upon the thermocycling indicates an existence of metastable states in the charge density wave phase, and it is commonly attributed to additional phase transitions. The absence of strong experimental evidence of these transitions is collaborated with an opened dispute on the nature of charge density wave state in this material. Physical origins of this phenomenon, including a complex charge density wave domain structure of 1T-TiSe2, are being discussed in the second part of the work.

Download or read book Charge density Waves and Collective Dynamics in the Transition metal Dichalcogenides written by Andreas König and published by . This book was released on 2013 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Two Dimensional Transition Metal Dichalcogenides written by Chi Sin Tang and published by John Wiley & Sons. This book was released on 2023-11-08 with total page 357 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-Dimensional Transition-Metal Dichalcogenides Comprehensive resource covering rapid scientific and technological development of polymorphic two-dimensional transition-metal dichalcogenides (2D-TMDs) over a range of disciplines and applications Two-Dimensional Transition-Metal Dichalcogenides: Phase Engineering and Applications in Electronics and Optoelectronics provides a discussion on the history of phase engineering in 2D-TMDs as well as an in-depth treatment on the structural and electronic properties of 2D-TMDs in their respective polymorphic structures. The text addresses different forms of in-situ synthesis, phase transformation, and characterization methods for 2D-TMD materials and provides a comprehensive treatment of both the theoretical and experimental studies that have been conducted on 2D-TMDs in their respective phases. Two-Dimensional Transition-Metal Dichalcogenides includes further information on: Thermoelectric, fundamental spin-orbit structures, Weyl semi-metallic, and superconductive and related ferromagnetic properties that 2D-TMD materials possess Existing and prospective applications of 2D-TMDs in the field of electronics and optoelectronics as well as clean energy, catalysis, and memristors Magnetism and spin structures of polymorphic 2D-TMDs and further considerations on the challenges confronting the utilization of TMD-based systems Recent progress of mechanical exfoliation and the application in the study of 2D materials and other modern opportunities for progress in the field Two-Dimensional Transition-Metal Dichalcogenides provides in-depth review introducing the electronic properties of two-dimensional transition-metal dichalcogenides with updates to the phase engineering transition strategies and a diverse range of arising applications, making it an essential resource for scientists, chemists, physicists, and engineers across a wide range of disciplines.

Download or read book First principles Study of Charge Density Waves Electron phonon Coupling and Superconductivity in Transition metal Dichalcogenides written by YIZHI GE and published by . This book was released on 2013 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Another polymorph of TaSe2 is then investigated. We focus on the origin of the CDW instability in bulk and single-layer 2H-TaSe2. The role of interlayer interactions and the effect of spin-orbit coupling are examined. The results show that the CDW instability has weak dependence on interlayer interactions and spin-orbit coupling, which is in contrast to the closely related 2H-NbSe2 material, where the CDW ordering vector is predicted to depend on dimensionality.

Download or read book Density Waves In Solids written by George Gruner and published by CRC Press. This book was released on 2018-03-08 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: ?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.

Download or read book Theoretical Study of Charge Density Waves in Transition Metal Materials written by Junichi Okamoto and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Our results show that the multi-orbitals allow a spin-triplet interaction among electrons leading to different phase diagrams from the ones considered previously for similar models. Numerical results obtained by first-principles calculations are also briefly explained. Third, we consider the effects of dilute strong impurities on the charge-density wave in niobium diselenide, a transition metal dichalcogenide. We first explain the material and properties of its charge-density wave phase. Then, detailed analysis of a scanning tunneling microscopy measurement is presented. Next, we analytically and numerically study a phenomenological model relevant to the experiment. We show that the dilute strong impurities have little effects at large length scales compared to the average inter-impurity distance, leading to a topologically ordered phase with a (quasi-)long-range autocorrelation; this result is quite different from conventional pictures predicting short-range order with the proliferation of topological defects.

Download or read book Two Dimensional Transition Metal Dichalcogenides written by Alexander V. Kolobov and published by Springer. This book was released on 2016-07-26 with total page 545 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Charge Density Wave Transitions in the Transition Metal Dichalcogenides microform written by Gary K. Scott and published by National Library of Canada. This book was released on 1981 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Charge Density Wave Phenomena in Trigonal Transition Metal Dichalcogenides written by Charles Sayers and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Two Dimensional Transition Metal Dichalcogenides written by Chi Sin Tang and published by John Wiley & Sons. This book was released on 2023-11-14 with total page 357 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-Dimensional Transition-Metal Dichalcogenides Comprehensive resource covering rapid scientific and technological development of polymorphic two-dimensional transition-metal dichalcogenides (2D-TMDs) over a range of disciplines and applications Two-Dimensional Transition-Metal Dichalcogenides: Phase Engineering and Applications in Electronics and Optoelectronics provides a discussion on the history of phase engineering in 2D-TMDs as well as an in-depth treatment on the structural and electronic properties of 2D-TMDs in their respective polymorphic structures. The text addresses different forms of in-situ synthesis, phase transformation, and characterization methods for 2D-TMD materials and provides a comprehensive treatment of both the theoretical and experimental studies that have been conducted on 2D-TMDs in their respective phases. Two-Dimensional Transition-Metal Dichalcogenides includes further information on: Thermoelectric, fundamental spin-orbit structures, Weyl semi-metallic, and superconductive and related ferromagnetic properties that 2D-TMD materials possess Existing and prospective applications of 2D-TMDs in the field of electronics and optoelectronics as well as clean energy, catalysis, and memristors Magnetism and spin structures of polymorphic 2D-TMDs and further considerations on the challenges confronting the utilization of TMD-based systems Recent progress of mechanical exfoliation and the application in the study of 2D materials and other modern opportunities for progress in the field Two-Dimensional Transition-Metal Dichalcogenides provides in-depth review introducing the electronic properties of two-dimensional transition-metal dichalcogenides with updates to the phase engineering transition strategies and a diverse range of arising applications, making it an essential resource for scientists, chemists, physicists, and engineers across a wide range of disciplines.

Download or read book Two Dimensional Transition Metal Dichalcogenides written by Narayanasamy Sabari Arul and published by Springer. This book was released on 2019-07-30 with total page 355 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book 2D Metallic Transition Metal Dichalcogenides Fundamentals and Applications written by Sekhar Rout and published by . This book was released on 2022-08 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Owing to possession of idiosyncratic physical attributes together with inherent magnetism, superconductivity and charge-density-wave order leads to potential usage over diverse domains, e.g., high-end microelectronic strategies, energy conversion and storage, catalysis, etc. 2D metallic TMDs have clutched extensive contemplation in the current time. Upon a thorough revisitation of a great deal of relevant literature, a visible dearth of a comprehensive compendium regarding such substances has been deeply realized. This edited book is aimed at filling such a gap via the presentation of eight different chapters devoted to systematically discussing fundamentals and applications of 2D metallic TMDs, so as to enable the readers to attain an inclusive concept and adequate knowledge regarding such materials.

Download or read book On the Nature of Charge Density Waves Superconductivity and Their Interplay in 1T TiSe2 written by Chuan Chen and published by Springer Nature. This book was released on 2019-09-27 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents analytical theoretical studies on the interplay between charge density waves (CDW) and superconductivity (SC) in the actively studied transition-metal dichalcogenide 1T-TiSe2. It begins by reapproaching a years-long debate over the nature of the phase transition to the commensurate CDW (CCDW) state and the role played by the intrinsic tendency towards excitonic condensation in this system. A Ginzburg-Landau phenomenological theory was subsequently developed to understand the experimentally observed transition from commensurate to incommensurate CDW (ICDW) order with doping or pressure, and the emergence of a superconducting dome that coexists with ICDW. Finally, to characterize microscopically the effects of the interplay between CDW and SC, the spectrum of CDW fluctuations beyond mean-field was studied in detail. In the aggregate, the work reported here provides an encompassing understanding of what are possibly key microscopic underpinnings of the CDW and SC physics in TiSe2.

Download or read book Nuclear Spectroscopy on Charge Density Wave Systems written by T. Butz and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear magnetic resonance (NMR), nuclear quadrupole resonance (NQR), time differential perturbed angular correlations (TDPAC), and the Mössbauer effect (ME) have been applied to the study of charge density wave (CDW) systems. These hyperfine techniques provide unique tools to probe the structure and symmetry of commensurate CDWs, give a clear fingerprint of incommensurate CDWs, and are ideally suited for CDW dynamics. This book represents a new attempt in the series `Physics and Chemistry of Materials with Low-dimensional Structures' to bring together a consistent group of scientific results obtained by nuclear spectroscopy related to CDW phenomena in pseudo-one- and two-dimensional systems. The individual chapters contain: the theory of CDWs in chain-like transition metal tetrachalcogenides; NMR, NQR, TDPAC, and ME investigations of layered transition metal dichalcogenides; NMR studies of CDW-transport in chain-like NbSe3 and molybdenum bronzes; multinuclear NMR of KCP; high resolution NMR of organic conductors. This book is of interest to graduate students and all scientists who want to acquire a broader knowledge of nuclear spectroscopy techniques applied to CDW systems.

Download or read book Fabrication and Characterizations of Two dimensional Charge density wave Devices Operating at Room Temperature written by Maedeh Taheri and published by . This book was released on 2017 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: The charge-density-wave (CDW) phase is a macroscopic quantum state consisting of a periodic modulation of the electronic charge density which is accompanied by a periodic distortion of the atomic lattice in quasi-one-dimensional (1D) or layered quasi-two-dimensional (2D) metallic crystals. Several layered transition metal dichalcogenides (TMDs) reveal the CDW phase transitions at rather high temperatures. These transitions can be affected by environmental conditions, film thickness and applied electric bias. This thesis reports results of investigation focused on developing and optimizing fabrication procedures for devices implemented with a specific TMD - 1T polytype of TaS2. This material undergoes the transition from a nearly commensurate CDW phase to incommensurate CDW phase at 350 K. This phase transition is accompanied by a lattice reconstruction, which results in strong modifications of the material's electrical properties. The change in the electrical characteristics in the transition point can be used for fabricating oscillator devices operating at room temperature. In this thesis, I briefly outline CDW theoretical background and then, describe in details the fabrication steps required for such devices. Specifically, I describe exfoliation of the 2D material, protection from oxidation, transfer process, spin coating, electron beam lithography, metal deposition and lift-off process. The current-voltage characteristics of the resulting devices show reproducibly an abrupt change in electrical current and a hysteresis loop. The hysteresis loop can be used for building a voltage controlled oscillator. The low-frequency noise measurements have been conducted in a wide temperature range in order to elucidate the physical mechanism of the phase transition and electronic transport. The noise spectral density shows 1/f type spectrum with signature of the generation--recombination (G-R) bulges at some bias points (f is the frequency). The obtained results are important for developing the 2D electronic device technology based on CDW effects.

Download or read book Non Centrosymmetric Superconductors written by Ernst Bauer and published by Springer Science & Business Media. This book was released on 2012-01-10 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superconductivity in materials without inversion symmetry in the respective crystal structures occurs in the presence of antisymmetric spin-orbit coupling as a consequence of an emerging electric field gradient. The superconducting condensate is then a superposition of spin-singlet and spin-triplet Cooper pairs. This scenario accounts for various experimental findings such as nodes in the superconducting gap or extremely large upper critical magnetic fields. Spin-triplet pairing can occur in non-centrosymmetric superconductors in spite of Anderson’s theorem that spin-triplet pairing requires a crystal structure that exhibits inversion symmetry. This book, authored and edited by leading researchers in the field, is both an introduction to and overview on this exciting branch of novel superconductors. Its self-contained and tutorial style makes it particularly suitable for self-study and as source of teaching material for special seminars and courses. At the same time it constitutes an up-to-date and authoritative reference for anyone working in this exciting field.

Download or read book Proceedings of the International Conference on Atomic Molecular Optical Nano Physics with Applications written by Vinod Singh and published by Springer Nature. This book was released on 2022-03-14 with total page 657 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the proceedings of the International Conference on Atomic, Molecular, Optical and Nano-Physics with Applications (CAMNP 2019), organized by the Department of Applied Physics, Delhi Technological University, New Delhi, India. It presents experimental and theoretical studies of atoms, ions, molecules and nanostructures both at the fundamental level and on the application side using advanced technology. It highlights how modern tools of high-field and ultra-fast physics are no longer merely used to observe nature but can be used to reshape and redirect atoms, molecules, particles or radiation. It brings together leading researchers and professionals on the field to present and discuss the latest finding in the following areas, but not limited to: Atomic and Molecular Structure, Collision Processes, Data Production and Applications Spectroscopy of Solar and Stellar Plasma Intense Field, Short Pulse Laser and Atto-Second Physics Laser Technology, Quantum Optics and applications Bose Einstein condensation Nanomaterials and Nanoscience Nanobiotechnolgy and Nanophotonics Nano and Micro-Electronics Computational Condensed Matter Physics