Electrical switching in a magnetically intercalated transition metal dichalcogenide.

Advances in controlling the correlated behaviour of transition metal dichalcogenides have opened a new frontier of many-body physics in two dimensions. A field where these materials have yet to make a deep impact is antiferromagnetic spintronics-a relatively new research direction promising technologies with fast switching times, insensitivity to magnetic perturbations and reduced cross-talk1-3. Here, we present measurements on the intercalated transition metal dichalcogenide Fe1/3NbS2 that exhibits antiferromagnetic ordering below 42 K (refs. 4,5). We find that remarkably low current densities of the order of 104 A cm-2 can reorient the magnetic order, which can be detected through changes in the sample resistance, demonstrating its use as an electronically accessible antiferromagnetic switch. Fe1/3NbS2 is part of a larger family of magnetically intercalated transition metal dichalcogenides, some of which may exhibit switching at room temperature, forming a platform from which to build tuneable antiferromagnetic spintronic devices6,7

CDS wide slit time-series of EUV coronal bright points

Wide slit (90" x 240" ) movies of four Extreme Ultraviolet coronal bright points (BPs) obtained with the Coronal Diagnostic Spectrometer (CDS) on board the Solar and Heliospheric Observatory (SoHO) have been inspected. The wavelet analysis of the He I 584.34 Å, O V 629.73 Å and Mg VII/IX 368 Å time-series confirms the oscillating nature of the BPs, with periods ranging between 600 and 1100 s. In one case we detect periods as short as 236 s. We suggest that these oscillations are the same as those seen in the chromospheric network and that a fraction of the network bright points are most likely the cool footpoints of the loops comprising coronal bright points. These oscillations are interpreted in terms of global acoustic modes of the closed magnetic structures associated with BPs

Realization of Coherent Optically Dense Media via Buffer-Gas Cooling

We demonstrate that buffer-gas cooling combined with laser ablation can be used to create coherent optical media with high optical depth and low Doppler broadening that offers metastable states with low collisional and motional decoherence. Demonstration of this generic technique opens pathways to coherent optics with a large variety of atoms and molecules. We use helium buffer gas to cool 87Rb atoms to below 7 K and slow atom diffusion to the walls. Electromagnetically induced transparency (EIT) in this medium allows for 50% transmission in a medium with initial OD >70 and for slow pulse propagation with large delay-bandwidth products. In the high-OD regime, we observe high-contrast spectrum oscillations due to efficient four-wave mixing.Comment: 4 pages, 4 figures. V2: modified title, abstract, introduction, conclusion; added references; improved theoretical fit in figure 3(b); shortened slow light theory description; clarified simplicity of apparatus. Final version as published in Phys. Rev.

Improved Constraints on the Preferential Heating and Acceleration of Oxygen Ions in the Extended Solar Corona

We present a detailed analysis of oxygen ion velocity distributions in the extended solar corona, based on observations made with the Ultraviolet Coronagraph Spectrometer (UVCS) on the SOHO spacecraft. Polar coronal holes at solar minimum are known to exhibit broad line widths and unusual intensity ratios of the O VI 1032, 1037 emission line doublet. The traditional interpretation of these features has been that oxygen ions have a strong temperature anisotropy, with the temperature perpendicular to the magnetic field being much larger than the temperature parallel to the field. However, recent work by Raouafi and Solanki suggested that it may be possible to model the observations using an isotropic velocity distribution. In this paper we analyze an expanded data set to show that the original interpretation of an anisotropic distribution is the only one that is fully consistent with the observations. It is necessary to search the full range of ion plasma parameters to determine the values with the highest probability of agreement with the UVCS data. The derived ion outflow speeds and perpendicular kinetic temperatures are consistent with earlier results, and there continues to be strong evidence for preferential ion heating and acceleration with respect to hydrogen. At heliocentric heights above 2.1 solar radii, every UVCS data point is more consistent with an anisotropic distribution than with an isotropic distribution. At heights above 3 solar radii, the exact probability of isotropy depends on the electron density chosen to simulate the line-of-sight distribution of O VI emissivity. (abridged abstract)Comment: 19 pages (emulateapj style), 13 figures, ApJ, in press (v. 679; May 20, 2008

Exploring industry level capabilities in the UK Creative Industries

The competitive dynamics of the UK’s Creative Industries has changed considerably over the past decade and perhaps none more so than in the Publishing Industry. There is no doubt that this industry continues to undergo structural changes that compel firms to adapt and transform their business in response to the dynamic nature of competitive environment. Industries have long been examined by researchers from a strategic perspective with various themes of inquiry relating to; industry structure and positioning, industry evolution and development, industry lifecycle, industry change and industry consolidation. This paper argues that ‘industry analysis’ could usefully draw on Dynamic Capabilities Theory which argues for the strategic adaptation and reconfiguration of firm resources and capabilities in order to address a rapidly changing competitive environment. This paper will present empirical findings from a comparative time-series analysis (1997-2014) of the UK Publishing Industry and compare it to other industries categorised within the UK’s Creative Industries. In doing so, this analysis will add to the limited knowledge base on industry level dynamic capabilities and extend our knowledge on inter-industry comparisons in performance following the reconfiguration of industry resources