Controlling the superconducting transition by spin-orbit coupling

Whereas there exists considerable evidence for the conversion of singlet Cooper pairs into triplet Cooper pairs in the presence of inhomogeneous magnetic fields, recent theoretical proposals have suggested an alternative way to exert control over triplet generation: intrinsic spin-orbit coupling in a homogeneous ferromagnet coupled to a superconductor. Here, we proximity-couple Nb to an asymmetric Pt/Co/Pt trilayer, which acts as an effective spin-orbit coupled ferromagnet owing to structural inversion asymmetry. Unconventional modulation of the superconducting critical temperature as a function of in-plane and out-of- plane applied magnetic fields suggests the presence of triplets that can be controlled by the magnetic orientation of a single homogeneous ferromagnet. Our studies demonstrate for the first time an active role of spin-orbit coupling in controlling the triplets -- an important step towards the realization of novel superconducting spintronic devices.Comment: 11 pages + 4 figures + supplemental informatio

CCS in the European Energy Transition to Climate Neutrality

The transition of the European energy system to reach climate neutrality by 2050 will require a development and deployment of technologies capable of decarbonizing the energy system in an unprecedented scale. Increased sector integration through electrification and system-wide application of hydrogen necessitates the coherent consideration of all energy sectors for transition planning and facilitation through an improved policy framework. The Hydrogen for Europe study has applied energy system models to analyse the potential role of hydrogen in all sectors, and in coexistence with electricity and other energy carriers. The current work focuses on the role of CCS as it emerged from this analysis, and how limitations in deployment rate of CCS impacts the energy transition. It was shown that limits on both the annual CO2 injection rate and minimum usage of renewable energy significantly affects the chosen route for hydrogen production.publishedVersio

CCS in the European Energy Transition to Climate Neutrality

The transition of the European energy system to reach climate neutrality by 2050 will require a development and deployment of technologies capable of decarbonizing the energy system in an unprecedented scale. Increased sector integration through electrification and system-wide application of hydrogen necessitates the coherent consideration of all energy sectors for transition planning and facilitation through an improved policy framework. The Hydrogen for Europe study has applied energy system models to analyse the potential role of hydrogen in all sectors, and in coexistence with electricity and other energy carriers. The current work focuses on the role of CCS as it emerged from this analysis, and how limitations in deployment rate of CCS impacts the energy transition. It was shown that limits on both the annual CO2 injection rate and minimum usage of renewable energy significantly affects the chosen route for hydrogen production

Enhanced controllable triplet proximity effect in superconducting spin–orbit coupled spin valves with modified superconductor/ferromagnet interfaces

In a superconductor/ferromagnet hybrid, a magnetically controlled singlet-to-triplet Cooper pair conversion can modulate the superconducting critical temperature. In these triplet superconducting spin valves, such control usually requires inhomogeneous magnetism. However, in the presence of spin–orbit coupling from an interfacial heavy metal layer, the singlet/triplet conversion rate and, thus, critical temperature can be controlled via the magnetization direction of a single homogeneous ferromagnet. Here, we report significantly enhanced controllable pair conversion to a triplet state in a Nb/Pt/Co/Pt superconducting spin valve in which Pt/Co/Pt is homogenously magnetized and proximity-coupled to a superconducting layer of Nb. The Co/Pt interface furthest away from Nb is modified by a sub-nanometer-thick layer of Cu or Au. We argue that the enhancement is most likely associated from an improvement of the Co/Pt interface due to the insertion of Cu and Au layers. Additionally, the higher normalized orbital moments in Au measured using x-ray magnetic circular dichroism shows that increasing spin–orbit coupling enhances the triplet proximity effect—an observation supported by our theoretical calculations. Our results provide a pathway to enhancing triplet pair creation by interface engineering for device development in superspintronics.</p

Imputation of incomplete large‐scale monitoring count data via penalized estimation

In biodiversity monitoring, large datasets are becoming more and more widely available and are increasingly used globally to estimate species trends and conservation status. These large-scale datasets challenge existing statistical analysis methods, many of which are not adapted to their size, incompleteness and heterogeneity. The development of scalable methods to impute missing data in incomplete large-scale monitoring datasets is crucial to balance sampling in time or space and thus better inform conservation policies. We developed a new method based on penalized Poisson models to impute and analyse incomplete monitoring data in a large-scale framework. The method allows parameterization of (a) space and time factors, (b) the main effects of predictor covariates, as well as (c) space–time interactions. It also benefits from robust statistical and computational capability in large-scale settings. The method was tested extensively on both simulated and real-life waterbird data, with the findings revealing that it outperforms six existing methods in terms of missing data imputation errors. Applying the method to 16 waterbird species, we estimated their long-term trends for the first time at the entire North African scale, a region where monitoring data suffer from many gaps in space and time series. This new approach opens promising perspectives to increase the accuracy of species-abundance trend estimations. We made it freely available in the r package ‘lori’ (https://CRAN.R-project.org/package=lori) and recommend its use for large-scale count data, particularly in citizen science monitoring programmes