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Photonics integrated circuitry would benefit considerably from the ability to arbitrarily control waveguide cross-sections with high precision and low loss, in order to provide more degrees of freedom in manipulating propagating light. Here, we report on a new optical-fibres-compatible glass waveguide by femtosecond laser writing, namely spherical phase induced multi-core waveguide (SPIM-WG), which addresses this challenging task with three dimensional on-chip light control. Precise deformation of cross-sections is achievable along the waveguide, with shapes and sizes finely controllable of high resolution in both horizontal and vertical transversal directions. We observed that these waveguides have high refractive index contrast of 0.017, low propagation loss of 0.14 dB/cm, and very low coupling loss of 0.19 dB coupled from a single mode fibre. SPIM-WG devices were easily fabricated that were able to perform on-chip beam rotation through varying angles, or manipulate polarization state of propagating light for target wavelengths. We also demonstrated SPIM-WG mode converters that provide arbitrary adiabatic mode conversion with high efficiency between symmetric and asymmetric non-uniform modes; examples include circular, elliptical modes and asymmetric modes from ppKTP waveguides which are generally applied in frequency conversion and quantum light sources. Created inside optical glass, these waveguides and devices have the capability to operate across ultra-broad bands from visible to infrared wavelengths. The compatibility with optical fibre also paves the way toward packaged photonic integrated circuitry, which usually needs input and output fibre connections.

La preocupación por el cuidado de la salud y el medio ambiente por parte de los consumidores de vino está aumentando en los últimos años, centrándose el interés en los vinos elaborados con prácticas de producción de bajo impacto en el uso de productos químico. Una de las estrategias potenciales es pasar de un enfoque orientado al tratamiento químico a un enfoque de prevención de enfermedades mediante la utilización de variedades resistentes a hongos, generalmente conocidas como uvas híbridas o cruzamientos interespecíficos. En este estudio, se investigaron los vinos elaborados a partir de cinco variedades resistentes cultivadas en el Instituto Estatal de Viticultura y Enología de Friburgo (Cabernet Cantor, Cabernet Cortis, Cabernet Carbon, Prior y Regent) y provenientes de parcelas experimentales ubicadas en la Provincia de Trento. Los vinos fueron sometidos a evaluación olfativa, y el perfil volátil estudiado por cromatografía de gases-olfatometría (GC-O). Las regiones seleccionadas de los cromatogramas fueron investigadas en detalle por GC-MS.

The interplay between strong spin-orbit coupling and electron correlations has recently been the subject of intense investigation, due to a number of theoretically predicted phases such as quantum spin liquids, unconventional superconductivity, complex magnetic orders, and correlated topological phases of matter. In particular, iridates have been proposed as a promising family of materials which could host a number of these phases. Here we report the existence of Dirac nodal lines in the binary oxide IrO2, through a combination of reactive oxide molecular beam epitaxy and angle-resolved photoemission spectroscopy. Unlike in other such materials reported to date, these Dirac nodal lines have the unique property of being simultaneously (i) robust against spin-orbit coupling, as they are protected by the nonsymmorphic symmetry of the rutile structure, and (ii) only partially occupied, since they cross the Fermi level. This should have direct implications on the low-energy physics properties tied to the band velocity such as magnetoresistance and spin Hall effect.

The layered van der Waals antiferromagnet MnBi2Te4 has been predicted to combine the band ordering of archetypical topological insulators such as Bi2Te3 with the magnetism of Mn, making this material a viable candidate for the realization of various magnetic topological states. We have systematically investigated the surface electronic structure of MnBi2Te4(0001) single crystals by use of spin- and angle-resolved photoelectron spectroscopy experiments. In line with theoretical predictions, the results reveal a surface state in the bulk band gap and they provide evidence for the influence of exchange interaction and spin-orbit coupling on the surface electronic structure., We acknowledge financial support from the DFG through SFB1170 ’Tocotronics’, SFB1143 ’Correlated Magnetism’, SPP 1666 ’Topological insulators’, ERA-Chemistry Programm (RU-776/15-1), and the Wurzburg-Dresden Cluster of ¨Excellence on Complexity and Topology in Quantum Matter – ct.qmat (EXC 2147, project-id 39085490). We also acknowledge the support by Spanish Ministerio de Economia y Competitividad (MINECO Grant No. FIS2016-75862-P), Academic D.I. Mendeleev Fund Program of Tomsk State University (Project No. 8.1.01.2018), the Saint Petersburg State University grant for scientic investigations (Grant No. 15.61.202.2015), and Russian Foundation for Basic Research (Grant No. 18-52-06009). S.M. acknowledges support by the Swiss National Science Foundation (Grant No. P300P2-171221). This research used resources of the Advanced Light Source, which is a DOE Office of Science User Facility under contract no. DE-AC02-05CH11231. We acknowledge Diamond Light Source for access to beamline I05 (proposals No. SI19278 and No. SI22468) that contributed to the results presented here. Parts of this research were carried out at PETRA III (DESY, Hamburg, Germany) under Proposal No. I-20180510. This work has been partly performed in the framework of the Nanoscience Foundry and Fine Analysis (NFFA-MIUR, Italy) facility. M.M.O. acknowledges support by the Diputacion Foral de Gipuzkoa ((SAREA 2018 - RED ´2018, project no. 2018-CIEN-000025-01).

In two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDs), new electronic phenomena such as tunable bandgaps 1-3 and strongly bound excitons and trions emerge from strong many-body effects 4-6 , beyond the spin and valley degrees of freedom induced by spin-orbit coupling and by lattice symmetry 7 . Combining single-layer TMDs with other 2D materials in van der Waals heterostructures offers an intriguing means of controlling the electronic properties through these many-body effects, by means of engineered interlayer interactions 8-10 . Here, we use micro-focused angle-resolved photoemission spectroscopy (microARPES) and in situ surface doping to manipulate the electronic structure of single-layer WS 2 on hexagonal boron nitride (WS 2 /h-BN). Upon electron doping, we observe an unexpected giant renormalization of the spin-orbit splitting of the single-layer WS 2 valence band, from 430 meV to 660 meV, together with a bandgap reduction of at least 325 meV, attributed to the formation of trionic quasiparticles. These findings suggest that the electronic, spintronic and excitonic properties are widely tunable in 2D TMD/h-BN heterostructures, as these are intimately linked to the quasiparticle dynamics of the materials 11-13 .

© 2017 American Chemical Society. The unique electronic band structure of indium nitride InN, part of the industrially significant III-N class of semiconductors, offers charge transport properties with great application potential due to its robust n-type conductivity. Here, we explore the water sensing mechanism of InN thin films. Using angle-resolved photoemission spectroscopy, core level spectroscopy, and theory, we derive the charge carrier density and electrical potential of a two-dimensional electron gas, 2DEG, at the InN surface and monitor its electronic properties upon in situ modulation of adsorbed water. An electric dipole layer formed by water molecules raises the surface potential and accumulates charge in the 2DEG, enhancing surface conductivity. Our intuitive model provides a novel route toward understanding the water sensing mechanism in InN and, more generally, for understanding sensing material systems beyond InN.

‘Memorandum submitted by Professor Iain McLean and Dr Scott Moser, Nuffield College, Oxford University’ in House of Commons, Procedure Committee, Election of the Speaker and of the Deputy Speakers, First Report of Session 2009-10. HC 341, pp. Ev5-Ev9.

We investigate the polaronic ground state of anatase TiO2 by bulk-sensitive resonant inelastic x-ray spectroscopy (RIXS) at the Ti L-3 edge. We find that the formation of the polaron cloud involves a single 95 meV phonon along the c axis, in addition to the 108 meV ab-plane mode previously identified by photoemission. The coupling strength to both modes is the same within error bars, and it is unaffected by the carrier density. These data establish RIXS as a directional bulk-sensitive probe of electron-phonon coupling in solids.

We investigate the evolution of both the occupied and unoccupied electronic structure in representative compounds of the infinitely adaptive superlattice series (Sb2)m-Sb2Te3 (m = 0–3) by means of angle-resolved photoemission spectroscopy and time-delayed two-photon photoemission, combined with first-principles band-structure calculations. We discover that the topological nature of the surface states and their spin texture are robust, with dispersions evolving from linear (Dirac-like) to parabolic (Rashba-like) along the series, as the materials evolve from semiconductors to semimetals. Our findings provide a promising strategy for engineering the topological states with the desired flexibility needed for realizing different quantum phenomena and spintronics applications.

A conceptual design is presented for a high power cupronickel pion production target. It forms a circular band in a horizontal plane with approximate dimensions of: 2.5 meters radius, 6 cm high and 0.6 cm thick. The target is continuously rotated at 3 m/s to carry heat away from the production region to a water cooling channel. Bunches of 16 GeV protons with total energies of 270 kJ and repetition rates of 15 Hz are incident tangentially to arc of the target along the symmetry axis of a 20 Tesla solenoidal magnetic capture channel. The mechanical layout and cooling setup are described. Results are presented from realistic MARS Monte Carlo computer simulations of the pion yield and energy deposition in the target. ANSYS finite element calculations are beginning to give predictions for the resultant shock heating stresses., Comment: 3 pages, 8 figures

Cryofixation is considered to be the best method for immobilizing biological material in its natural state. In jet-freezing, the specimen typically is sandwiched between two carriers and kept in place while a coolant is moved very rapidly against the opposite surfaces. The JFD 030 jet-freezing device has been used to optimize the operating parameters. The course of the temperature in place of a specimen was measured with thermocouples and recorded by an IBM-compatible personal computer using a specifically developed software program. Mean cooling rates, over the temperature range of 273K to 173K, achievable with different cryogens, including the non-flammable HCFC 124 (SUVA 124-CHClFCF3), were measured under a variety of conditions. The freezing capability of the JFD 030 was evaluated by analyzing transmission electron microscopic results obtained from freeze-substituted plant cells and freeze-fractured cosmetic emulsions. Jet-freezing, despite its limits in freezing thick specimens, can be applied to cell suspensions as well as to semi-thin sections by the use of thin Ti supports, a higher pressure of the nitrogen gas or by a brief pretreatment with a cryoprotectant (e.g., sucrose). In addition, with the non-flammable HCFC 124 in combination with the thin Ti supports, freezing rates similar to those achievable with propane and standard copper supports can be reached giving researchers the chance to use jet-freezing without the dangerous propane.

'Chardonnay' (n = 4), 'Pinot gris' (n = 3) and 'Müller-Thurgau' juices (n = 3), each at 6 turbidity levels (15, 45, 86, 141, 215 and 350 NTU) obtained by adding increasing amounts of their own fine juice lees, were fermented using 'Montrachet Red Star' yeast. The main volatile compounds in free form which may have a sensory role were measured using GC-FID, with a DB-WAX column, after fixing onto Isolute ENV+ resin. Changes for around 40 volatile compounds and fermentation parameters are shown. Juice turbidity levels just below 100 NTU are the best compromise for obtaining adequate fruity notes and minimising languishing fermentation and off-flavours in white wine, if correct microbiology management at the winery is guaranteed, whereas slightly higher NTU levels could contribute to a slightly more complex aroma. However, variability due to juice turbidity in the range investigated is lower than variability due to yeast strain observed in a previous experiment. Thus the choice of yeast strain to direct white wine aroma must be overriding as compared to NTU levels., VITIS - Journal of Grapevine Research, Vol. 50 No. 3 (2011): Vitis