Noise Sensitivities for an Atom Shuttled by a Moving Optical Lattice via Shortcuts to Adiabaticity

We find the noise sensitivities (i.e., the quadratic terms of the energy with respect to the perturbation of the noise) of a particle shuttled by an optical lattice that moves according to a shortcut-to-adiabaticity transport protocol. Noises affecting different optical lattice parameters, trap depth, position, and lattice periodicity, are considered. We find generic expressions of the sensitivities for arbitrary noise spectra but focus on the white-noise limit as a basic reference, and on Ornstein–Uhlenbeck noise to account for the effect of non-zero correlation times.

Curie-Weiss behavior of liquid structure and ideal glass state

We present the results of a structural study of metallic alloy liquids from high temperature through the glass transition. We use high energy X-ray scattering and electro-static levitation in combination with molecular dynamics simulation and show that the height of the first peak of the structure function, S(Q) − 1, follows the Curie-Weiss law. The structural coherence length is proportional to the height of the first peak, and we suggest that its increase with cooling may be related to the rapid increase in viscosity. The Curie temperature is negative, implying an analogy with spin-glass. The Curie-Weiss behavior provides a pathway to an ideal glass state, a state with long-range correlation without lattice periodicity, which is characterized by highly diverse local structures, reminiscent of spin-glass.

Copper nanoparticles prepared by pulsed exploding wire

In this work copper nanopowder was created at different liquidmedias like DDDW, ethylene glycol and Polyvinylpyrrolidone(PVP). Copper nanopowder prepared using explosion wire processand investigated the effects of the exploding energy, wire diameter,the type of liquid on the particle size, and the particles sizedistribution. The nanoparticles are characterized by x-ray diffraction,UV-visible absorption spectroscopy and transmission electronmicroscopy (TEM). The x-ray diffraction results reveal that thenanoparticles continue to routine lattice periodicity at reducedparticle size. The UV-Visible absorption spectrum of liquid solutionfor copper nanoparticles shows sharp and single surface Plasmonresonance (SPR) peak centered at a wavelength of 590 nm inethylene glycol media, but don’t have peak in PVP fluid. This peakindicated the production of pure and spherical copper nanoparticle.

Aperiodic Crystals

Until the 1970s all materials studied consisted of periodic arrays of unit cells, or were amorphous. In the following decades a new class of solid state matter, called aperiodic crystals, has been found. It is a long-range ordered structure, but without lattice periodicity. It is found in a wide range of materials: organic and inorganic compounds, minerals (including a substantial portion of the earth’s crust), and metallic alloys, under various pressures and temperatures. Because of the lack of periodicity the usual techniques for the study of structure and physical properties no longer work, and new techniques have to be developed. This book deals with the characterization of the structure, the structure determination, and the study of the physical properties, especially the dynamical and electronic properties of aperiodic crystals. The treatment is based on a description in a space with more dimensions than three, the so-called superspace. This allows us to generalize the standard crystallography and to look differently at the dynamics. The three main classes of aperiodic crystals, modulated phases, incommensurate composites, and quasicrystals are treated from a unified point of view which stresses the similarities of the various systems. The book assumes as a prerequisite a knowledge of the fundamental techniques of crystallography and the theory of condensed matter, and covers the literature at the forefront of the field.

Aperiodic Crystals

2014 is the International Year of Crystallography. During at least fifty years after the discovery of diffraction of X-rays by crystals, it was believed that crystals have lattice periodicity, and crystals were defined by this property. Now it has become clear that there is a large class of compounds with interesting properties that should be called crystals as well, but are not lattice periodic. A method has been developed to describe and analyze these aperiodic crystals, using a higher-dimensional space. In this lecture the discovery of aperiodic crystals and the development of the formalism of the so-called superspace will be described. There are several classes of such materials. After the incommensurate modulated phases, incommensurate magnetic crystals, incommensurate composites and quasicrystals were discovered. They could all be studied using the same technique. Their main properties of these classes and the ways to characterize them will be discussed. The new family of aperiodic crystals has led also to new physical properties, to new techniques in crystallography and to interesting mathematical questions. Much has been done in the last fifty years by hundreds of crystallographers, crystal growers, physicists, chemists, mineralogists and mathematicians. Many new insights have been obtained. But there are still many questions, also of fundamental nature, to be answered. We end with a discussion of these open questions.

Wide Range Solid Solutions with Composite Modulated Structures

Systems that form modulated structures are a fascinating class of materials, which lack lattice periodicity but may still be perfectly long-range ordered [1]. Such systems exist across the whole range of chemical disciplines from organic conductors to high-Tc superconductors and minerals. The importance of modulated structures has been recognised, but there have been few systematic studies across composition ranges of wide-range solid solutions that form composite modulated structures. Such a systematic investigations further our understanding of crystal chemical and structural aspects of modulated structures as well as the reasons for their existence. Examples for such wide-range solid solutions will be presented, with structures investigated using X-ray and neutron powder diffraction as well as transmission electron microscopy.

Aperiodic crystals and superspace concepts

For several decades the lattice periodicity of crystals, as shown by Laue, was considered to be their essential property. In the early sixties of the last century compounds were found which for many reasons should be called crystals, but were not lattice periodic. This opened the field of aperiodic crystals. An overview of this development is given. Many materials of this kind were found, sometimes with very interesting properties. In the beginning the development was slow, but the number of structures of this type increased enormously. In the meantime hundreds of scientists have contributed to this field using a multi-disciplinary approach.