Download or read book Magnetic Heat Transport in Low dimensional Quantum Spin Systems written by Oleg Mityashkin and published by . This book was released on 2013 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetic Heat Transport in Low dimensional Quantum Magnets written by Marian Otter and published by . This book was released on 2012 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetic Field Effects in Low Dimensional Quantum Magnets written by Adam Iaizzi and published by Springer. This book was released on 2018-11-28 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is a tour-de-force combination of analytic and computational results clarifying and resolving important questions about the nature of quantum phase transitions in one- and two-dimensional magnetic systems. The author presents a comprehensive study of a low-dimensional spin-half quantum antiferromagnet (the J-Q model) in the presence of a magnetic field in both one and two dimensions, demonstrating the causes of metamagnetism in such systems and providing direct evidence of fractionalized excitations near the deconfined quantum critical point. In addition to describing significant new research results, this thesis also provides the non-expert with a clear understanding of the nature and importance of computational physics and its role in condensed matter physics as well as the nature of phase transitions, both classical and quantum. It also contains an elegant and detailed but accessible summary of the methods used in the thesis—exact diagonalization, Monte Carlo, quantum Monte Carlo and the stochastic series expansion—that will serve as a valuable pedagogical introduction to students beginning in this field.
Download or read book Magnetic Light Scattering in Low dimensional Quantum Spin Systems written by P. Lemmens and published by . This book was released on 2003 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transport Studies of Quantum Magnetism written by and published by . This book was released on 2017 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main goal of this project was to understand novel ground states of spin systems probed by thermal and electrical transport measurements. They are well-suited to characterize the nature of low-energy excitations as unique property of the ground state. More specifically, it was aimed to study the transverse electrical conductivity in the presence of non-collinear and non-coplanar spin ordering and the effects of gauge field as well as novel spin excitations as a coherent heat transport channel in insulating quantum magnets. Most of works done during the grant period focused on these topics. As a natural extension of the project's initial goals, the scope was broadened to include transport studies on the spin systems with strong spin-orbit coupling. One particular focus was an exploration of systems with strong magnetic anisotropy combined with non-trivial spin configuration. Magnetic anisotropy is directly related to implement the non-collinear spin ordering to the existing common geometry of planar devices and thus poses a significant potential. Work in this direction includes the comparison of the topological Hall signal under hydrostatic pressure and chemical doping, as well as the angular dependence dependence of the non-collinear spin ordered phase and their evolution up on temperature and field strength. Another focus was centered around the experimental identification of spin-originated heat carrying excitation in quasi two dimensional honeycomb lattice, where Kitaev type of quantum spin liquid phase is expected to emerge. In fact, when its long range magnetic order is destroyed by the applied field, we discovered anomalously large enhancement of thermal conductivity, for which proximate Kitaev excitations in field-induced spin liquid state are responsible for. This work, combined with further investigations in materials in the similar class may help establish the experimental characterization of new quantum spin liquid and their unique low energy excitation, e.g. Majorana fermions.
Download or read book Magnetic Light Scattering in Low dimensional Quantum Spin Systems written by P. Lemmens and published by . This book was released on 2003 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetic Characteristics of Metal Organic Low dimensional Quantum Spin Systems at Low Temperatures written by Katarina Remović-Langer and published by . This book was released on 2010 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Low Dimensional Spin Systems Studied in High Magnetic Fields written by Christopher Mennerich and published by . This book was released on 2008 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetoelectric Response in Low Dimensional Frustrated Spin Systems written by and published by Springer. This book was released on 2012-08-31 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Low dimensional Quantum Magnets written by and published by . This book was released on 2014 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book DFT based Microscopic Magnetic Modeling for Low dimensional Spin Systems written by Oleg Janson and published by . This book was released on 2012 with total page 223 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermodynamic Characterization of Heavy Fermion Systems and Low Dimensional Quantum Magnets Near a Quantum Critical Point written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report experimentally results on the low temperature properties of two classes of materials with a special emphasizes near the QCP induced by substitution and magnetic 1.field: (1) the HF systems YbRh2(Si0.95Ge0.05)2, Yb1-yLayRh2Si2 (y = 0.05, 0.1), and YbIr2Si2 with tetragonal structures and CeIn3-xSnx (x = 0.55, 0.6, 0.65, 0.7, 0.8) with cubic structure; (2) the quantum spin systems: Cs2CuCl4 and Cs2CoCl4. In all the HF compounds we have observed NFL behavior in zero magnetic field close to the QCP. The La substituted system does not show an antiferromagnetic (AFM) transition down to the lowest accessible temperature (0.03 K) while in YbRh2(Si1-xGex)2 with x = 0 and x = 0.05 AFM transitions occur at TN =0.07 K and 0.02 K, respectively. For Yb0.9La0.1Rh2Si2 we observe below 0.07 K saturation of DeltaC/T indicating clearly a LFL state for this concentration. For YbIr2Si2, DeltaC/T saturates below 0.5 K. In contrast to the Yb based compounds in the vicinity of the QCP, CeIn3-xSnx shows no evidence of a divergence in Delta C/T, with B or with x. Furthermore, we used specic heat measurements in the mK temperature range and at high fields (up to 12 T) to probe the phase diagrams in the low dimensional quantum antiferromagnets Cs2CuCl4 and Cs2CoCl4. In applied magnetic field, we have presented experimental evidence that in Cs2CuCl4 the field dependence of the critical temperature Tc(B) ~ (Bc-B)^1-Phi close to the critical field Bc = 8.51 T is well described with Phi=1.5. This is in very good agreement with the exponent expected in the mean-field approximation and support the notion of a Bose-Einstein condensation of magnons in Cs2CuCl4.
Download or read book Dynamics of One dimensional Quantum Spin Systems with Competing Interactions at Zero Temperature written by Yongmin Yu and published by . This book was released on 1996 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterizing Ground States of Low dimensional Quantum Magnets written by Hyejin Ju and published by . This book was released on 2013 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of frustration in quantum magnetism has been the focus of extensive research in the past couple of decades. The class of materials in this category is typically strongly correlated, due to strong electron-electron repulsion. In one- and two-dimensions, quantum fluctuations dominate these systems, and often, semi-classical approximations become an oversimplification. This thesis is concerned with exploring exotic physics that can emerge in low-dimensional quantum magnets. First, we use a T = 0 projected Monte Carlo algorithm in the valence bond basis to study the entanglement scaling of two-dimensional (2d) gapless systems. In particular, we focus on the resonating-valence-bond wavefunction as well as the gapless Goldstone mode in the Heisenberg model on the square lattice. We find that, in addition to the area law, there is a subleading, shape-dependent piece to the entanglement entropy, which is reminiscent of one dimensional (1d) gapless systems. We then explore the Heisenberg model under an applied magnetic field on the quasi-1d problem of a three-leg triangular spin tube (TST), using extensive density-matrix-renormalization group calculations coupled with analytical arguments to describe the results. We find that the physics describing this model differs from some of the well-known results on the two dimensional lattice, especially near low magnetic fields and at 1/3 magnetization. Finally, further research and possibilities in numerical techniques are discussed.
Download or read book Dynamics and Thermodynamics of Nonlinear Low dimensional Magnetic and Electromagnetic Systems microform written by Oleg N. Vassiliev and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 2001 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results of a theoretical study of low-dimensional nonlinear systems are reported. One system is the isotropic Heisenberg ferromagnet with long range spin-spin interactions. The spin coupling parameter depends as the power law r-p on the distance r between spins. One-dimensional chains, two-dimensional square lattices, and two-layer films are considered as specific examples. The thermodynamic properties of these systems are investigated in a broad range of the parameter p using the Handscomb quantum Monte-Carlo method. The phase behavior and properties of the spin correlation functions are determined, and the critical indices and the temperature of the phase transition are calculated. Another system studied in this thesis is a dielectric multilayer structure with planar interfaces. In each of the layers the dielectric constant is generally a nonlinear function of the electric field. A new formalism is developed to study propagation of nonlinear optical waves in such a structure. The formalism is applied to a thin film sandwiched between two semi-infinite media and to an infinite periodic superlattice. Properties of the waves and the dispersion relations are investigated numerically.
Download or read book Temperature Versus Composition Phase Diagrams and Spin Glass Behavior in Low Dimensional Mixed Magnetic Systems written by Gerald Victor Rubenacker and published by . This book was released on 1988 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Strong Interactions in Low Dimensions written by D. Baeriswyl and published by Springer Science & Business Media. This book was released on 2007-09-29 with total page 441 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an attempt to convey the colorful facets of condensed matter systems with reduced dimensionality. Some of the specific features predicted for interacting one-dimensional electron systems, such as charge- and spin-density waves, have been observed in many quasi-one-dimensional materials. The two-dimensional world is even richer: besides d-wave superconductivity and the Quantum Hall Effect - perhaps the most spectacular phases explored during the last two decades - many collective charge and spin states have captured the interest of researchers, such as charge stripes or spontaneously generated circulating currents. Recent years have witnessed important progress in material preparation, measurement techniques and theoretical methods. Today larger and better samples, higher flux for neutron beams, advanced light sources, better resolution in electron spectroscopy, new computational algorithms, and the development of field-theoretical approaches allow an in-depth analysis of the complex many-body behaviour of low-dimensional materials. The epoch when simple mean-field arguments were sufficient for describing the gross features observed experimentally is definitely over. The Editors' aim is to thoroughly explain a number of selected topics: the application of dynamical probes, such as neutron scattering, optical absorption and photoemission, as well as transport studies, both electrical and thermal. Some of the more theoretical chapters are directly relevant for experiments, such as optical spectroscopy, transport in one-dimensional models, and the phenomenology of charge inhomogeneities in layered materials, while others discuss more general topics and methods, for example the concept of a Luttinger liquid and bosonization, or duality transformations, both promising tools for treating strongly interacting many-body systems.
