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The splitting of zero-energy Majorana modes in a tunnel-coupled InAs nanowire with epitaxial aluminium is exponentially suppressed as the wire length is increased, resulting in protection of these modes; this result helps to establish the robust presence of Majorana modes and quantifies exponential protection in nanowire devices. Majorana modes get more real There are three known fundamental types of fermions called Dirac, Weyl and Majorana. Until recently, the latter two had escaped observation, but evidence for the existence of Weyl and Majorana modes was found in condensed matter systems. In particular, signatures for Majorana modes were identified in semiconductor–superconductor nanowire devices, and this sparked significant interest because non-trivial topological properties had been predicted. Charles Marcus and colleagues present the next essential piece of evidence for the robust presence of Majorana modes in such devices, namely the exponential protection of Majorana modes in the form of a suppression of energy splitting with increasing nanowire length. The observations open a path to the next step of controlling Majorana modes and establishing topological properties. Majorana zero modes are quasiparticle excitations in condensed matter systems that have been proposed as building blocks of fault-tolerant quantum computers 1 . They are expected to exhibit non-Abelian particle statistics, in contrast to the usual statistics of fermions and bosons, enabling quantum operations to be performed by braiding isolated modes around one another 1 , 2 . Quantum braiding operations are topologically protected insofar as these modes are pinned near zero energy, with the departure from zero expected to be exponentially small as the modes become spatially separated 3 , 4 . Following theoretical proposals 5 , 6 , several experiments have identified signatures of Majorana modes in nanowires with proximity-induced superconductivity 7 , 8 , 9 , 10 , 11 and atomic chains 12 , with small amounts of mode splitting potentially explained by hybridization of Majorana modes 13 , 14 , 15 . Here, we use Coulomb-blockade spectroscopy in an InAs nanowire segment with epitaxial aluminium, which forms a proximity-induced superconducting Coulomb island (a ‘Majorana island’) that is isolated from normal-metal leads by tunnel barriers, to measure the splitting of near-zero-energy Majorana modes. We observe exponential suppression of energy splitting with increasing wire length. For short devices of a few hundred nanometres, sub-gap state energies oscillate as the magnetic field is varied, as is expected for hybridized Majorana modes. Splitting decreases by a factor of about ten for each half a micrometre of increased wire length. For devices longer than about one micrometre, transport in strong magnetic fields occurs through a zero-energy state that is energetically isolated from a continuum, yielding uniformly spaced Coulomb-blockade conductance peaks, consistent with teleportation via Majorana modes 16 , 17 . Our results help to explain the trivial-to-topological transition in finite systems and to quantify the scaling of topological protection with end-mode separation.

Stakeholder theory suggests a relationship between corporate social responsibility (CSR) and corporate financial performance (CFP) because certain stakeholders reward certain types of CSR. This argument assumes that stakeholders attend to firms' CSR activities—an assumption that has yet to be examined. We fill this gap by extending stakeholder theory to the context of stakeholder attention to firm CSR and exploring the antecedents and consequences of stakeholder attention to corporate disaster relief CSR. We test the resulting hypotheses on a sample of public companies that engaged in natural disaster relief efforts, finding that stakeholder attention partially mediated the relationship between disaster relief and CFP and that stakeholder attention to corporate disaster relief was driven by the legitimacy, urgency, and enactment of disaster relief CSR initiatives.

On the NASA 2020 rover mission to Jezero crater, the remote determination of the texture, mineralogy and chemistry of rocks is essential to quickly and thoroughly characterize an area and to optimize the selection of samples for return to Earth. As part of the Perseverance payload, SuperCam is a suite of five techniques that provide critical and complementary observations via Laser-Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman and Luminescence (TRR/L), visible and near-infrared spectroscopy (VISIR), high-resolution color imaging (RMI), and acoustic recording (MIC). SuperCam operates at remote distances, primarily 2–7 m, while providing data at sub-mm to mm scales. We report on SuperCam’s science objectives in the context of the Mars 2020 mission goals and ways the different techniques can address these questions. The instrument is made up of three separate subsystems: the Mast Unit is designed and built in France; the Body Unit is provided by the United States; the calibration target holder is contributed by Spain, and the targets themselves by the entire science team. This publication focuses on the design, development, and tests of the Mast Unit; companion papers describe the other units. The goal of this work is to provide an understanding of the technical choices made, the constraints that were imposed, and ultimately the validated performance of the flight model as it leaves Earth, and it will serve as the foundation for Mars operations and future processing of the data.

Controlling the properties of semiconductor/metal interfaces is a powerful method for designing functionality and improving the performance of electrical devices. Recently semiconductor/superconductor hybrids have appeared as an important example where the atomic scale uniformity of the interface plays a key role in determining the quality of the induced superconducting gap. Here we present epitaxial growth of semiconductor–metal core–shell nanowires by molecular beam epitaxy, a method that provides a conceptually new route to controlled electrical contacting of nanostructures and the design of devices for specialized applications such as topological and gate-controlled superconducting electronics. Our materials of choice, InAs/Al grown with epitaxially matched single-plane interfaces, and alternative semiconductor/metal combinations allowing epitaxial interface matching in nanowires are discussed. We formulate the grain growth kinetics of the metal phase in general terms of continuum parameters and bicrystal symmetries. The method realizes the ultimate limit of uniform interfaces and seems to solve the soft-gap problem in superconducting hybrid structures. Molecular beam epitaxy now enables the growth of nanowire heterostructures composed of a semiconducting core and a metallic epitaxial shell. This improved synthesis leads to the creation of a hard superconducting gap with no subgap states.

How mild-to-moderate hypertriglyceridemia (2-10 mmol/L; 177-886 mg/dL) potentially causes acute pancreatitis is unknown; however, cellular studies indicate that inflammation might be a driver of disease progression. We tested the hypotheses that ( ) mild-to-moderate hypertriglyceridemia is associated with low-grade inflammation and that ( ) the association between mild-to-moderate hypertriglyceridemia and risk of acute pancreatitis depends on low-grade inflammation. From the Copenhagen General Population Study and the Copenhagen City Heart Study, 117865 men and women 20-100+ years of age with measurements of nonfasting plasma triglycerides at baseline were followed prospectively for development of acute pancreatitis. After multivariable adjustment, a 1 mmol/L (89 mg/dL) higher nonfasting triglyceride concentration was associated with 17% (95% CI, 16%-18%, = 3 × 10 ) higher plasma C-reactive protein (CRP) and a 4.2% (4.0%-4.4%, = 6 × 10 ) higher blood leukocyte count. Higher concentrations of nonfasting triglycerides were associated almost linearly with higher risk of acute pancreatitis ( for trend = 5 × 10 ), with hazard ratios of 1.5 (95% CI, 0.9-2.5), 2.0 (95% CI, 1.1-3.6), 2.2 (95% CI, 1.0-4.7), 4.2 (95% CI, 1.6-11.5), and 7.7 (95% CI, 3.0-19.8) in individuals with nonfasting triglycerides of 1.00-1.99 mmol/L (89-176 mg/dL; 46% of the population), 2.00-2.99 mmol/L (177-265 mg/dL; 17%), 3.00-3.99 mmol/L (266-353 mg/dL; 6%), 4.00-4.99 mmol/L (354-442 mg/dL; 2%), and ≥5mmol/L(443 mg/dL; 2%), respectively, vs individuals with <1 mmol/L (89 mg/dL; 27%). The association with risk of acute pancreatitis appeared more pronounced in individuals with CRP of ≥1.39 mg/L ( for trend = 0.001) and leukocytes of ≥7 × 10 /L ( = 2 × 10 ) than in those with CRP <1.39 mg/L ( = 0.03) and leukocytes <7 × 10 /L ( = 0.04); however, there was no formal evidence of statistical interaction ( = 0.38 for CRP and = 0.41 for leukocytes). Mild-to-moderate hypertriglyceridemia is associated with low-grade inflammation and higher risk of acute pancreatitis. The association between mild-to-moderate hypertriglyceridemia and risk of acute pancreatitis is possibly partly mediated by low-grade inflammation.

It remains unclear whether musical training is associated with improved speech understanding in a noisy environment, with different studies reaching differing conclusions. Even in those studies that have reported an advantage for highly trained musicians, it is not known whether the benefits measured in laboratory tests extend to more ecologically valid situations. This study aimed to establish whether musicians are better than non-musicians at understanding speech in a background of competing speakers or speech-shaped noise under more realistic conditions, involving sounds presented in space via a spherical array of 64 loudspeakers, rather than over headphones, with and without simulated room reverberation. The study also included experiments testing fundamental frequency discrimination limens (F0DLs), interaural time differences limens (ITDLs), and attentive tracking. Sixty-four participants (32 non-musicians and 32 musicians) were tested, with the two groups matched in age, sex, and IQ as assessed with Raven’s Advanced Progressive matrices. There was a significant benefit of musicianship for F0DLs, ITDLs, and attentive tracking. However, speech scores were not significantly different between the two groups. The results suggest no musician advantage for understanding speech in background noise or talkers under a variety of conditions.

A magnetic impurity coupled to a superconductor gives rise to a Yu–Shiba–Rusinov (YSR) state inside the superconducting energy gap. With increasing exchange coupling the excitation energy of this state eventually crosses zero and the system switches to a YSR ground state with bound quasiparticles screening the impurity spin by ħ /2. Here we explore indium arsenide (InAs) nanowire double quantum dots tunnel coupled to a superconductor and demonstrate YSR screening of spin-1/2 and spin-1 states. Gating the double dot through nine different charge states, we show that the honeycomb pattern of zero-bias conductance peaks, archetypal of double dots coupled to normal leads, is replaced by lines of zero-energy YSR states. These enclose regions of YSR-screened dot spins displaying distinctive spectral features, and their characteristic shape and topology change markedly with tunnel coupling strengths. We find excellent agreement with a simple zero-bandwidth approximation, and with numerical renormalization group calculations for the two-orbital Anderson model. Coupling superconductors to mesoscopic systems leads to unusual effects that could be exploited in new devices including topological quantum computers. Here the authors present a double quantum dot with a Yu–Shiba–Rusinov ground state arising from the interplay of Coulomb interactions and superconductivity.

HDL is quantitatively the most important lipoprotein in most species and mechanistic evidence points toward a role for HDL in normal immune function. We tested the hypothesis that concentrations of HDL cholesterol are associated with risk of autoimmune disease. From 2 studies of the general population-the Copenhagen General Population Study and the Copenhagen City Heart study-we included 107954 and 9387 individuals with baseline measurements of HDL cholesterol. These were followed with the national Danish Patient Registry from baseline in 2003-2015 or 1991-1994 through 2017, during which time 4078 and 1101 individuals developed autoimmune disease in the 2 studies. In the Copenhagen General Population Study, compared to individuals with HDL cholesterol ≥2.0 mmol/L (77 mg/dL), the multifactorially adjusted hazard ratios for any autoimmune disease were 1.06 (95% CI, 0.94-1.19) for individuals with HDL cholesterol of 1.5-1.99 mmol/L (58-77 mg/dL), 1.18 (95% CI, 1.04-1.35) for individuals with HDL cholesterol of 1.0-1.49 mmol/L (39-58 mg/dL), and 1.84 (95% CI, 1.52-2.22) for individuals with HDL cholesterol <1.0 mmol/L (39 mg/dL) ( for trend <0.001). These results were similar when excluding events within 5 years of baseline, in women and men separately, for events at baseline, irrespective of low-grade inflammation or triglyceride concentrations, for the apolipoprotein A1 part of HDL, and for more restrictive end point definitions. Finally, the Copenhagen City Heart Study provided independent confirmation. Low HDL cholesterol level is associated with high risk of autoimmune disease in individuals from the general population. Our observational findings cannot determine causality.