21,667 research outputs found
Kondo resonance narrowing in d- and f-electron systems
By developing a simple scaling theory for the effect of Hund's interactions
on the Kondo effect, we show how an exponential narrowing of the Kondo
resonance develops in magnetic ions with large Hund's interaction. Our theory
predicts an exponential reduction of the Kondo temperature with spin S of the
Hund's coupled moment, a little-known effect first observed in d-electron
alloys in the 1960's, and more recently encountered in numerical calculations
on multi-band Hubbard models with Hund's interactions. We discuss the
consequences of Kondo resonance narrowing for the Mott transition in d-band
materials, particularly iron pnictides, and the narrow ESR linewidth recently
observed in ferromagnetically correlated f-electron materials.Comment: 4 pages, 3 figure
Multipole Expansions of Aggregate Charge: How Far to Go?
Aggregates immersed in a plasma or radiative environment will have charge
distributed over their extended surface. Previous studies have modeled the
aggregate charge using the monopole and dipole terms of a multipole expansion,
with results indicating that the dipole-dipole interactions play an important
role in increasing the aggregation rate and altering the morphology of the
resultant aggregates. This study examines the effect that including the
quadrupole terms has on the dynamics of aggregates interacting with each other
and the confining electric fields in laboratory experiments. Results are
compared to modeling aggregates as a collection of point charges located at the
center of each spherical monomer comprising the aggregate.Comment: 6 page
The Role Of Local Authorities In Health Issues: A Policy Document Analysis
Prior to the passing of the Health and Social Care Act 2012 the Communities and Local Government (CLG) Select Committee conducted an investigation into the proposed changes to the Public Health System in England. The Committee considered 40 written submissions and heard oral evidence from 26 expert witnesses. Their report, which included complete transcripts of both oral and written submissions, provided a rich and informed data on which to base an analysis of the proposed new public health system. This report analyses the main themes that emerged from the evidence submissions and forms part of our preliminary work for PRUComm’s PHOENIX project examining the development of the new public health system
Non-Singular Stationary Global Strings
A field-theoretical model for non-singular global cosmic strings is
presented. The model is a non-linear sigma model with a potential term for a
self-gravitating complex scalar field. Non-singular stationary solutions with
angular momentum and possibly linear momentum are obtained by assuming an
oscillatory dependence of the scalar field on t, phi and z. This dependence has
an effect similar to gauging the global U(1) symmetry of the model, which is
actually a Kaluza-Klein reduction from four to three spacetime dimensions. The
method of analysis can be regarded as an extension of the
gravito-electromagnetism formalism beyond the weak field limit. Some D=3
self-dual solutions are also discussed.Comment: 20 pages Latex, 12 PS figures included. Minor corrections. Version to
appear in Phys.Rev.
In the Forests Up in Grand Old Maine
https://digitalcommons.library.umaine.edu/mmb-me/1107/thumbnail.jp
Quantum Reciprocity Conjecture for the Non-Equilibrium Steady State
By considering the lack of history dependence in the non-equilibrium steady
state of a quantum system we are led to conjecture that in such a system, there
is a set of quantum mechanical observables whose retarded response functions
are insensitive to the arrow of time, and which consequently satisfy a quantum
analog of the Onsager reciprocity relations. Systems which satisfy this
conjecture can be described by an effective Free energy functional. We
demonstrate that the conjecture holds in a resonant level model of a multi-lead
quantum dot.Comment: References revised to take account of related work on Onsager
reciprocity in mesoscopics by Christen, and in hydrodynamics by Mclennan,
Dufty and Rub
Deconfined quantum criticality in the two dimensional Kondo lattice model
We investigate the continuous quantum phase transition from an
antiferromagnetic metal to a heavy fermion liquid based on the Kondo lattice
model in two dimensions. We propose that antiferromagnetic spin fluctuations
and conduction electrons fractionalize into neutral bosonic spinons and charged
spinless fermions at the quantum critical point. This deconfined quantum
criticality leads us to establish a critical field theory in terms of the
fractionalized fields interacting via emergent U(1) gauge fields. The critical
field theory not only predicts non-Fermi liquid physics near the quantum
critical point but also recovers Fermi liquid physics away from the quantum
critical point
Diphenylketene with Nitrogen Trichloride
Diphenylketene reacts with nitrogen trichloride in carbon tetrachloride solution. When this solution is warmed to 50° C with sodium hydroxide the addition product undergoes a rearrangement with the formation of imidobenzophenone. This rearrangement is similar to the rearrangement in Hofmann\u27s method for the preparation of primary amines from amides. On passing dry HCl into the carbon tetrachloride solution, the hydrochloride of this compound is precipitated
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