Atomic layer deposition of a MgO barrier for a passivated black phosphorus spintronics platform

We demonstrate a stabilized black phosphorus (BP) 2D platform thanks to an ultrathin MgO barrier, as required for spintronic device integration. The in-situ MgO layer deposition is achieved by using a large-scale atomic layer deposition process with high nucleation density. Raman spectroscopy studies show that this layer protects the BP from degradation in ambient conditions, unlocking in particular the possibility to carry out usual lithographic fabrication steps. The resulting MgO/BP stack is then integrated in a device and probed electrically, confirming the tunnel properties of the ultrathin MgO contacts. We believe that this demonstration of a BP material platform passivated with a functional MgO tunnel barrier provides a promising perspective for BP spin transport devices

Long-range propagation and interference of d-wave superconducting pairs in graphene

Resumen del trabajo presentado a la Conference Low dimensional superconducting hybrids for novel quantum functionalities, celebrada en Paris (Francia) del 12 al 14 de octubre de 2021.Peer reviewe

Variation of the mass-spring-mass resonance frequency of etics cladding systems in practice

With the increased awareness of environmental aspects, External Thermal Insulation Composite Systems (ETICS) are gaining interest. The main purpose of adding an ETICS cladding to a wall is to improve its thermal isolation. Whilst in the higher frequency range the acoustic performance is improved due to the application of ETICS cladding, in the lower frequency range the acoustic performance usually decreases. This reduction of the acoustic performance is caused by a mass-spring-mass resonance effect of the added thermal insulation layer with plaster covering. The paper presents experimentally obtained sound reduction indices, following ISO 10140-2, for a wall with and without ETICS cladding. The paper also reports on the observation of a significant variation of the mass-spring-mass resonance frequency of the ETICS cladding across the wall surface

Long-Range Propagation and Interference of d -Wave Superconducting Pairs in Graphene

Recent experiments have shown that proximity with high-temperature superconductors induces unconventional superconducting correlations in graphene. Here, we demonstrate that those correlations propagate hundreds of nanometers, allowing for the unique observation of d-wave Andreev-pair interferences in YBa2Cu3O7-graphene devices that behave as a Fabry-Perot cavity. The interferences show as a series of pronounced conductance oscillations analogous to those originally predicted by de Gennes-Saint-James for conventional metal-superconductor junctions. The present demonstration is pivotal to the study of exotic directional effects expected for nodal superconductivity in Dirac materials

The magnitude of the snow-sourced reactive nitrogen flux to the boundary layer in the Uintah Basin, Utah, USA

Reactive nitrogen (Nr  =  NO, NO2, HONO) and volatile organic carbon emissions from oil and gas extraction activities play a major role in wintertime ground-level ozone exceedance events of up to 140 ppb in the Uintah Basin in eastern Utah. Such events occur only when the ground is snow covered, due to the impacts of snow on the stability and depth of the boundary layer and ultraviolet actinic flux at the surface. Recycling of reactive nitrogen from the photolysis of snow nitrate has been observed in polar and mid-latitude snow, but snow-sourced reactive nitrogen fluxes in mid-latitude regions have not yet been quantified in the field. Here we present vertical profiles of snow nitrate concentration and nitrogen isotopes (δ15N) collected during the Uintah Basin Winter Ozone Study 2014 (UBWOS 2014), along with observations of insoluble light-absorbing impurities, radiation equivalent mean ice grain radii, and snow density that determine snow optical properties. We use the snow optical properties and nitrate concentrations to calculate ultraviolet actinic flux in snow and the production of Nr from the photolysis of snow nitrate. The observed δ15N(NO3−) is used to constrain modeled fractional loss of snow nitrate in a snow chemistry column model, and thus the source of Nr to the overlying boundary layer. Snow-surface δ15N(NO3−) measurements range from −5 to 10 ‰ and suggest that the local nitrate burden in the Uintah Basin is dominated by primary emissions from anthropogenic sources, except during fresh snowfall events, where remote NOx sources from beyond the basin are dominant. Modeled daily averaged snow-sourced Nr fluxes range from 5.6 to 71  ×  107 molec cm−2 s−1 over the course of the field campaign, with a maximum noontime value of 3.1  ×  109 molec cm−2 s−1. The top-down emission estimate of primary, anthropogenic NOx in Uintah and Duchesne counties is at least 300 times higher than the estimated snow NOx emissions presented in this study. Our results suggest that snow-sourced reactive nitrogen fluxes are minor contributors to the Nr boundary layer budget in the highly polluted Uintah Basin boundary layer during winter 2014