335 research outputs found
Broadband enhancement of the magneto-optical activity of hybrid Au loaded Bi:YIG
We unravel the underlying near-field mechanism of the enhancement of the
magneto-optical activity of bismuth-substituted yttrium iron garnet films
(Bi:YIG) loaded with gold nanoparticles. The experimental results show that the
embedded gold nanoparticles lead to a broadband enhancement of the
magneto-optical activity with respect to the activity of the bare Bi:YIG films.
Full vectorial near- and far-field simulations demonstrate that this broadband
enhancement is the result of a magneto-optically enabled cross-talking of
orthogonal localized plasmon resonances. Our results pave the way to the
on-demand design of the magneto-optical properties of hybrid magneto-plasmonic
circuitry.Comment: 6 Pages, 3 Figure
Topological States on the Gold Surface
Gold surfaces host special electronic states that have been understood as a
prototype of Shockley surface states (SSs). These SSs are commonly employed to
benchmark the capability of angle-resolved photoemission spectroscopy (ARPES)
and scanning tunneling spectroscopy. We find that these Shockley SSs can be
reinterpreted as topologically derived surface states (TDSSs) of a topological
insulator (TI), a recently discovered quantum state. Based on band structure
calculations, the Z2 topological invariant can be well defined to characterize
the nontrivial features of gold that we detect by ARPES. The same TDSSs are
also recognized on surfaces of other well-known noble metals (e.g., silver,
copper, platinum, and palladium). Besides providing a new understanding of
noble metal SSs, finding topological states on late transition metals provokes
interesting questions on the role of topological effects in surface-related
processes, such as adsorption and catalysis.Comment: 21 pages, 3 figure
Light-induced magnetization reversal of high-anisotropy TbCo alloy films
Magnetization reversal using circularly polarized light provides a new way to
control magnetization without any external magnetic field and has the potential
to revolutionize magnetic data storage. However, in order to reach ultra-high
density data storage, high anisotropy media providing thermal stability are
needed. Here, we evidence all-optical magnetization switching for different
TbxCo1-x ferrimagnetic alloy composition and demonstrate all-optical switching
for films with anisotropy fields reaching 6 T corresponding to anisotropy
constants of 3x106 ergs/cm3. Optical magnetization switching is observed only
for alloys which compensation temperature can be reached through sample
heating
Optical control of scattering, absorption and lineshape in nanoparticles
We find exact conditions for the enhancement or suppression of internal and/or scattered fields in any smooth particle and the determination of their spatial distribution or angular momentum through the combination of simple fields. The incident fields can be generated by a single monochromatic or broad band light source, or by several sources, which may also be impurities embedded in the nanoparticle. We can design the lineshape of a particle introducing very narrow features in its spectral response
Responsiveness of five condition-specific and generic outcome assessment instruments for chronic pain
<p>Abstract</p> <p>Background</p> <p>Changes of health and quality-of-life in chronic conditions are mostly small and require specific and sensitive instruments. The aim of this study was to determine and compare responsiveness, i.e. the sensitivity to change of five outcome instruments for effect measurement in chronic pain.</p> <p>Methods</p> <p>In a prospective cohort study, 273 chronic pain patients were assessed on the Numeric Rating Scale (NRS) for pain, the Short Form 36 (SF-36), the Multidimensional Pain Inventory (MPI), the Hospital Anxiety and Depression Scale (HADS), and the Coping Strategies Questionnaire (CSQ). Responsiveness was quantified by effect size (ES) and standardized response mean (SRM) before and after a four week in-patient interdisciplinary pain program and compared by the modified Jacknife test.</p> <p>Results</p> <p>The MPI measured pain more responsively than the SF-36 (ES: 0.85 vs 0.72, p = 0.053; SRM: 0.72 vs 0.60, p = 0.027) and the pain NRS (ES: 0.85 vs 0.62, p < 0.001; SRM: 0.72 vs 0.57, p = 0.001). Similar results were found for the dimensions of role and social interference with pain. Comparison in function was limited due to divergent constructs. The responsiveness of the MPI and the SF-36 was equal for affective health but both were better than the HADS (e.g. MPI vs HADS depression: ES: 0.61 vs 0.43, p = 0.001; SF-36 vs HADS depression: ES: 0.54 vs 0.43, p = 0.004). In the "ability to control pain" coping dimension, the MPI was more responsive than the CSQ (ES: 0.46 vs 0.30, p = 0.011).</p> <p>Conclusion</p> <p>The MPI was most responsive in all comparable domains followed by the SF-36. The pain-specific MPI and the generic SF-36 can be recommended for comprehensive and specific bio-psycho-social effect measurement of health and quality-of-life in chronic pain.</p
Tailoring the ferromagnetic surface potential landscape by a templating two-dimensional metal-organic porous network
Two-dimensional metal-organic porous networks (2D-MOPNs) have been identified
as versatile nanoarchitectures to tailor surface electronic and magnetic
properties on noble metals. In this context, we propose a protocol to
redecorate a ferromagnetic surface potential landscape using a 2D-MOPN.
Ultrathin cobalt (Co) films grown on Au(111) exhibit a well-ordered surface
triangular reconstruction. On the ferromagnetic surface, the adsorbed
2,4,6-tris(4-pyridyl)-1,3,5triazine (T4PT) molecules can coordinate with the
native Co atoms to form a large-scale Co-T4PT porous network. The Co-T4PT
network with periodic nanocavities serves as a templating layer to reshape the
ferromagnetic surface potential. The subsequently deposited C60 molecules are
steered by the network porous potential and the neighboring C60 interactions.
The prototype of the ferromagnetic-supported 2D-MOPN is a promising template
for the tailoring of molecular electronic and spin properties
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