Surface plasmon-mediated nanoscale localization of laser-driven sub-THz spin dynamics in magnetic dielectrics

Ultrafast all-optical control of spins with femtosecond laser pulses is one of the hot topics at the crossroads of photonics and magnetism with a direct impact on future magnetic recording. Unveiling light-assisted recording mechanisms for an increase of the bit density beyond the diffraction limit without excessive heating of the recording medium is an open challenge. Here we show that surface plasmon-polaritons in hybrid metal-dielectric structures can provide spatial confinement of the inverse Faraday effect, mediating the excitation of localized coherent spin precession with 0.41 THz frequency. We demonstrate a two orders of magnitude enhancement of the excitation efficiency at the surface plasmon resonance within the 100 nm layer in dielectric garnet. Our findings broaden the horizons of ultrafast spin-plasmonics and open pathways towards non-thermal opto-magnetic recording at the nano-scale

Morphological Features of Tyrosine Hydroxylase Immunoreactive Cells in the Mouse Islets of Langerhans

The current immunohistochemical study used the antibody against tyrosine hydroxylase (TH) to observe the immunoreactive elements in the mouse pancreas. The results indicated the presence of immunoreactive nerve fibers and endocrine cells. The immunopositive nerve fibers appeared as thick and thin bundles; thick bundles were seen to run along the blood vessels giving out fine fibers to the wall. Varicose nerve fibers were seen in the islets of Langerhans and also in close association with the exocrine endpieces. The TH immunoreactive cells were oval-round in shape and some showed the central non-staining area and the dense staining peripheral zone. More than 80% of the islets of Langerhans contained the immunoreactive cells. Individual islet showed between 3-10 immunopositive cells and a few contained 1-2 cells. The TH immunopositive cells were widely distributed in the islets; they were seen in the centre, at the intermediate position and at the periphery of the islets. The exact role of the TH immunoreactive cells in the islets of Langerhans is not known. It is possible that they secrete tyrosine hydroxylase that may have some paracrine influence to the endocrine cells. Wide distribution of these cells in the islets indicates that they may regulate the entire population of the islets cells.Keywords: Balb/c mouse, Pancreas, Islet of Langerhans, Tyrosine Hydroxylase, Immunohistochemistr

Effect of Boundary-Layer Development on the Water-Surface Fluctuations of Supercritical Flow below a Sluice Gate

Hydraulic structures with a sluice gate are commonly used for control of the flow. In supercritical flow below a sluice gate, an accurate estimation of the water depth and boundary layer thickness is important for the hydraulic design of a horizontal apron. The relation between water-surface fluctuations and boundary-layer development has not been clarified. The aim of this paper is to experimentally demonstrate the effect of boundary-layer development on water-surface fluctuations of supercritical flow below a sluice gate. It is shown that water surface begins to fluctuate slightly upstream of the critical point. The water-surface fluctuations and turbulence intensities downstream of the critical point are also obtained, which demonstrates the length required for the water-surface fluctuations and turbulence intensity distributions to nearly equal uniform open-channel flow

Anisotropic magnetic fluctuations in the ferromagnetic superconductor UCoGe studied by angle-resolved ^{59}Co NMR

We have carried out direction-dependent ^{59}Co NMR experiments on a single crystal sample of the ferromagnetic superconductor UCoGe in order to study the magnetic properties in the normal state. The Knight shift and nuclear spin-lattice relaxation rate measurements provide microscopic evidence that both static and dynamic susceptibilities are ferromagnetic with strong Ising anisotropy. We discuss that superconductivity induced by these magnetic fluctuations prefers spin-triplet pairing state.Comment: 4 pages, 4 figure

Shared Responsibilities for Nuclear Disarmament: A Global Debate

Presents Sagan's 2009 paper calling for rethinking the balance of responsibilities and the relationship between articles in the Nuclear Non-Proliferation Treaty with seven response papers by international scholars about how to pursue nuclear disarmament

Intelligent environments: a manifesto

We explain basic features of an emerging area called Intelligent Environments. We give a short overview on how it has developed, what is the current state of the art and what are the challenges laying ahead. The aim of the article is to make aware the Computer Science community of this new development, the differences with previous dominant paradigms and the opportunities that this area offers to the scientific community and society

Molecular dynamics analysis for the brownian motion of nano bubble

The smaller bubble whose diameter is below 1 micrometer is called nanobubble or ultra-fine bubble. The size of nano bubble is so small and invisible that the diameter distribution is generally evaluated as a mean square distance(MSD) of brownian motion that is measured by Dynamic Light Scattering(DLS) method based on the Einstein-Stokes equation. The equation, however, is not clarified for the application to the bubble sizing. In our previous study, the different behavior between solid particle and bubble with the same diameter at sub-micro scale was confirmed. In this study, the Brownian motion of nano bubble as well as the solid Pt particle whose diameter are around a few nano meters were simulated with the Molecular Dynamics(MD) method. The simulation employed Lennard Jones(LJ) potential to estimate the MSD of the bubbles and particles by tracing the trajectories of the center of gravity of them and resulted that the displacement of solid particles in liquid argon was less than the predicted amount by the Einstein-Stokes equation. In order to confirm apparent viscosity caused by periodic boundary conditions, the drop velocity of the particle due to the gravity force is measured and apparent viscosity is obtained using Stokes’ low with this velocity. Considering this apparent viscosity, the diameter of the solid particle is approximated using the Einstein-Stokes equation under its diameter of 4 nm. The bubble diameter obtained by the Brownian motion is lower than the Einstein-Stokes equatio

Observation of the Interference Effect of Electron-Capture X-rays from Radioisotopes

開始ページ、終了ページ: 冊子体のページ付

Superconductivity induced by longitudinal ferromagnetic fluctuations in UCoGe

From detailed angle-resolved NMR and Meissner measurements on a ferromagnetic (FM) superconductor UCoGe (T_Curie ~ 2.5 K and T_SC ~ 0.6 K), we show that superconductivity in UCoGe is tightly coupled with longitudinal FM spin fluctuations along the c axis. We found that magnetic fields along the c axis (H || c) strongly suppress the FM fluctuations and that the superconductivity is observed in the limited magnetic field region where the longitudinal FM spin fluctuations are active. These results combined with model calculations strongly suggest that the longitudinal FM spin fluctuations tuned by H || c induce the unique spin-triplet superconductivity in UCoGe. This is the first clear example that FM fluctuations are intimately related with superconductivity.Comment: 4 pages, 5 figures, to appear in PR