Matter systems condensation disorder

NMR Studies of Disorder in Condensed Matter Systems K. P. Ramesh... 

Disorder in condensed matter system is a vast area of research and has seen tremendous progress due to the addition of new systems and techniques. Nuclear magnetic resonance (NMR) being a local probe has played an important role in exploring the rich physics hidden in these systems. 

It is my pleasure to present Volume 71 of Annual Reports on NMR, which consists of a collection of reports on advances in many scientific areas due to the application of NMR techniques. The volume commences with an account of Magnetic Resonance of Systems with Equivalent Spin-1/2 Nuclides by J.A. Weil Protein Dynamics as Reported by NMR is presented by Z. Gaspari and A. Perczel Virtual MRS Spectral Simulation and its Applications is covered by B.J. Soher, K. Young and L. Kaiser F.H. Larsen reports on Simulation of Molecular Motion of Quadrupolar Nuclei in Solid State NMR finally, NMR Studies of Disorder in Condensed Matter Systems is discussed by K.P. Ramesh. My thanks are due to all of these reporters for their interesting and timely contributions. 

Systems exhibiting both strong disorder and electron correlation, so-caUed disordered Mott-Hubbard insulators, are difficult to evaluate. The description of electronic states in the presence of both disorder and correlation is still an unresolved issue in condensed matter physics. Whether disorder or the correlation is the predominant factor in controlling transport properties in a material depends on a complex... 

Figure II. Density of states (DOS) of vibrational and electronic excitation in condensed matter systems and in molecular systems. The DOS for electronic and vibrational excitation in condensed matter systems is continuous, and is characterized by van Hove topological singularities for ordered structures and by exponential Mott tails for disordered materials. The DOS for electronic excitation of molecular systems is discrete below the first ionization potential. In molecular systems the vibrational DOS is discrete, while in large molecules a quasicontinuum of vibrational states exists at high energies.

The basic modem data describing the atomic stmcture of matter have been obtained by the using of diffraction methods - X-ray, neutron and electron diffraction. All three radiations are used not only for the stmcture analysis of various natural and synthetic crystals - inorganic, metallic, organic, biological crystals but also for the analysis of other condensed states of matter - quasicrystals, incommensurate phases, and partly disordered system, namely, for high-molecular polymers, liquid crystals, amorphous substances and liquids, and isolated molecules in vapours or gases. This tremendous... 

We dedicate here a limited space to these aspects of theoretical and computational description of hquids because this chapter specifically addresses interaetion potentials and because other approaches will be used and described in other chapters of the Handbook. Several other approaches have the QM formulation more in the background, often never mentioned. Such models are of a more classical nature, with a larger phenomenological character. We quote as examples the models to describe light diffraction in disordered systems, the classical models for evaporation, condensation and dissolution, the transport of the matter in the hquid. The number is fairly large, especially in passing to dynamical and... 

In condensed matter physics, the effects of disorder, defects, and impurities are relevant for many materials properties hence their understanding is of utmost importance. The effects of randomness and disorder can be dramatic and have been investigated for a variety of systems covering a wide field of complex phenomena [109]. Examples include the pinning of an Abrikosov flux vortex lattice by impurities in superconductors [110], disorder in Ising magnets [111], superfluid transitions of He in a porous medium [112], and phase transitions in randomly confined smectic liquid crystals [113, 114]. 

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