Instability due to long range Coulomb interaction in a liquid of polarizable particles (polarons, etc.)

The interaction Hamiltonian for a system of polarons a la Feynman in the presence of long range Coulomb interaction is derived and the dielectric function is computed in mean field. For large enough concentration a liquid of such particles becomes unstable. The onset of the instability is signaled by the softening of a collective optical mode in which all electrons oscillate in phase in their respective self-trapping potential. We associate the instability with a metallization of the system. Optical experiments in slightly doped cuprates and doped nickelates are analyzed within this theory. We discuss why doped cuprates matallize whereas nickelates do not.Comment: 5 pages,1 figur

Model ab initio study of charge carrier solvation and large polaron formation on conjugated carbon chains

Using long C_{N}H_{2} conjugated carbon chains with the polyynic structure as prototypical examples of one-dimensional (1D) semiconductors, we discuss self-localization of excess charge carriers into 1D large polarons in the presence of the interaction with a surrounding polar solvent. The solvation mechanism of self-trapping is different from the polaron formation due to coupling with bond-length modulations of the underlying atomic lattice well-known in conjugated polymers. Model ab initio computations employing the hybrid B3LYP density functional in conjunction with the polarizable continuum model are carried out demonstrating the formation of both electron- and hole-polarons. Polarons can emerge entirely due to solvation but even larger degrees of charge localization occur when accompanied by atomic displacements

Tilting instability and other anomalies in the flux-lattice in some magnetic superconductors

The flux-line lattice in the compound $ErNi_2B_2C$, which has a tendency to ferromagnetic order in the a-b plane is studied with external magnetic field direction close to the c-axis. We show the existence of an instability where the direction of flux-lines spontaneously tilts away from that of the applied field near the onset of ferromagnetic order. The enhanced fluctuations in the flux lattice and the square flux lattice recently observed are explained and further experiments suggested.Comment: 12 pages, Latex file, no figur

SDGs, Inclusive Health and the path to Universal Health Coverage. Disability and The Global South

The Sustainable Development Goals (SDGs) are a set of goals designed to improve the social, economic and well-being of all, while maintaining global and environmental sustainability. Health is one of the 17 goals, and focuses not only on addressing morbidity and mortality, but also on improving access to healthcare services for all through Universal Health Coverage (UHC). While disability is not specifically mentioned in this goal, a focus on people with disabilities is important given the inclusive nature of the SDGs and the fact that people with disabilities make up the largest minority group in the world. This paper aims to critically consider what the health goal could mean for people with disabilities and advocates for inclusive health. It discusses the complex relationship between disability and health, and why people with disabilities are more vulnerable to poor health are discussed, and then considers factors that impact access to quality healthcare for people with disabilities and how these impact on the achievement of the targets in SDG Health Goal and the main principles of UHC. The paper argues that developing an inclusive approach to healthcare will not only improve achieving good health for all, but is also important since experiencing poor health may reduce quality of life and participation (e.g. in education, employment or community activities). Poor quality of life and participation can exacerbate disability, poverty and exclusion in addition to increasing suffering, morbidity and early mortality. The paper concludes that an inclusive UHC will not only fulfil the fundamental rights of people with disabilities to health and rehabilitation, as emphasized within the UN Convention on the Rights of Persons with Disabilities, but also contribute to the achievement of the SDGs

Phonon Coherence and New Set of Sidebands in Phonon-Assisted Photoluminescence

We investigate excitonic polaron states comprising a local exciton and phonons in the longitudinal optical (LO) mode by solving the Schr\"{o}dinger equation. We derive an exact expression for the ground state (GS), which includes multi-phonon components with coefficients satisfying the Huang-Rhys factors. The recombination of GS and excited polaron states gives one set of sidebands in photoluminescence (PL): the multi-phonon components in the GS produce the Stokes lines and the zero-phonon components in the excited states produce the anti-Stokes lines. By introducing the mixing of the LO mode and environal phonon modes, the exciton will also couple with the latter, and the resultant polaron states result in another set of phonon sidebands. This set has a zero-phonon line higher and wider than that of the first set due to the tremendous number of the environal modes. The energy spacing between the zero-phonon lines of the first and second sets is proved to be the binding energy of the GS state. The common exciton origin of these two sets can be further verified by a characteristic Fano lineshape induced by the coherence in the mixing of the LO and the environal modes.Comment: 5 pages, 3 figures 1 figure (fig. 1) replaced 1 figure (fig. 2) remove

MC-128: current commutator for silicon strip detector tests

The MC-128 is a CAMAC module designed to simplify routine tests of multichannel semiconductor detectors. It was developed at Budker Institute of Nuclear Physics (BINP) Novosibirsk in collaboration with RD2 as part of the ATLAS SCT development program. The module provides 128 channels, offering sequential measurements of the currents flowing grom detector strips to a grounded Common Bus. Each input stays virtually connected to the Common Bus independently on whether its current is measured or not. Eight inputs are permanently connected to the Common Bus, allowing the connection of additional elements like guard ring structures. The total detector current can be measured as the current flowing through the Common Bus. Measurements are accessible via a CAMAC bus and in analog form via a front panel detector. Optionally, the MC 128 allows the measurement of the capacitance between each strip and the common (high voltage) electrode of the detector at 10 kHz frequency

Quantum Simulations of Extended Hubbard Models with Dipolar Crystals

In this paper we study the realization of lattice models in mixtures of atomic and dipolar molecular quantum gases. We consider a situation where polar molecules form a self-assembled dipolar lattice, in which atoms or molecules of a second species can move and scatter. We describe the system dynamics in a master equation approach in the Brownian motion limit of slow particles and fast phonons, which we find appropriate for our system. In a wide regime of parameters, the reduced dynamics of the particles leads to physical realizations of extended Hubbard models with tuneable long-range interactions mediated by crystal phonons. This extends the notion of quantum simulation of strongly correlated systems with cold atoms and molecules to include phonon-dynamics, where all coupling parameters can be controlled by external fields.Comment: 44 pages, 14 figure

An exactly solvable phase transition model: generalized statistics and generalized Bose-Einstein condensation

In this paper, we present an exactly solvable phase transition model in which the phase transition is purely statistically derived. The phase transition in this model is a generalized Bose-Einstein condensation. The exact expression of the thermodynamic quantity which can simultaneously describe both gas phase and condensed phase is solved with the help of the homogeneous Riemann-Hilbert problem, so one can judge whether there exists a phase transition and determine the phase transition point mathematically rigorously. A generalized statistics in which the maximum occupation numbers of different quantum states can take on different values is introduced, as a generalization of Bose-Einstein and Fermi-Dirac statistics.Comment: 17 pages, 2 figure

Effects of fluorine implantation on the kinetics of dry oxidation of silicon

Kinetics of dry oxidation of silicon after implantation of fluorine in the oxide layer are investigated. It appeared that implanted fluorine can result in negative values of the linear oxidation rate constant. Fluorine profiles obtained by the nuclear reaction analysis (NRA) method using a resonant 19F(α, p)22Ne nuclear reaction will be presented. At 1200 °C the fluorine moves to the interface of Si and SiO2, both in dry oxidizing and inert atmospheres. Based on these findings, a model is presented that explains quantitatively the observed anomalous behavior of the linear oxidation rate constant