Interfacially Enhanced Superconductivity in Fe(Te,Se)/Bi4Te3 Heterostructures.

Realizing topological superconductivity by integrating high-transition-temperature (TC) superconductors with topological insulators can open new paths for quantum computing applications. Here, a new approach is reported for increasing the superconducting transition temperature ( T C onset ) $( {T_{\mathrm{C}}^{{\mathrm{onset}}}} )$ by interfacing the unconventional superconductor Fe(Te,Se) with the topological insulator Bi-Te system in the low-Se doping regime, near where superconductivity vanishes in the bulk. The critical finding is that the T C onset $T_{\mathrm{C}}^{{\mathrm{onset}}}$ of Fe(Te,Se) increases from nominally non-superconducting to as high as 12.5 K when Bi2Te3 is replaced with the topological phase Bi4Te3. Interfacing Fe(Te,Se) with Bi4Te3 is also found to be critical for stabilizing superconductivity in monolayer films where T C onset $T_{\mathrm{C}}^{{\mathrm{onset}}}$ can be as high as 6 K. Measurements of the electronic and crystalline structure of the Bi4Te3 layer reveal that a large electron transfer, epitaxial strain, and novel chemical reduction processes are critical factors for the enhancement of superconductivity. This novel route for enhancing TC in an important epitaxial system provides new insight on the nature of interfacial superconductivity and a platform to identify and utilize new electronic phases.

Reconfigurable Resistive Switching in VO2/La0.7Sr0.3MnO3/Al2O3 (0001) Memristive Devices for Neuromorphic Computing.

The coexistence of nonvolatile and volatile switching modes in a single memristive device provides flexibility to emulate both neuronal and synaptic functions in the brain. Furthermore, such a device structure may eliminate the need for additional circuit elements such as transistor-based selectors, enabling low-power consumption and high-density device integration in fully memristive spiking neural networks. In this work, we report dual resistive switching (RS) modes in VO2/La0.7Sr0.3MnO3 (LSMO) bilayer memristive devices. Specifically, the nonvolatile RS is driven by the movement of oxygen vacancies (Vo) at the VO2/LSMO interface and requires a higher biasing voltage, whereas the volatile RS is controlled by the metal-insulator transition (MIT) of VO2 under a lower biasing voltage. The simple device structure is electrically driven between the two RS modes and thus can operate as a one selector-one resistor (1S1R) cell, which is a desirable feature in memristive crossbar arrays to avoid the sneak-path current issue. The RS modes are found to be stable and repeatable and can be reconfigured by exploiting the interfacial and phase transition properties, and thus, they hold great promise for applications in memristive neural networks and neuromorphic computing.

Autonomic and hedonic response to affective touch in autism spectrum disorder.

Interpersonal touch plays a crucial role in shaping relationships and encouraging social connections. Failure in processing tactile input or abnormal tactile sensitivity may hamper social behaviors and have severe consequences in individuals' relational lives. Autism Spectrum Disorder (ASD) is characterized by both sensory disruptions and social impairments, making affective touch an ideal meeting point for understanding these features in ASD individuals. By integrating behavioral and physiological measures, we investigated the effects of affective touch on adult individuals with ASD from both an implicit and explicit perspective. Specifically, at an implicit level, we investigated whether and how receiving an affective touch influenced participants' skin conductance tonic and phasic components. At the explicit level, we delved into the affective and unpleasant features of affective touch. Overall, we observed lower skin conductance level in ASD compared to TD subjects. Interestingly, the typically developing (TD) group showed an increased autonomic response for affective touch compared to a control touch, while ASD subjects' autonomic response did not differ between the two conditions. Furthermore, ASD participants provided higher ratings for both the affective and unpleasant components of the touch, compared to TD subjects. Our results reveal a noteworthy discrepancy in ASD population between the subjective experience, characterized by amplified hedonic but also unpleasant responses, and the physiological response, marked by a lack of autonomic activation related to affective touch. This insightful dissociation seems crucial for a deeper understanding of the distinctive challenges characterizing people with ASD and may have implications for diagnosis and therapeutic approaches.

Effects of prism adaptation and visual scanning training on perceptual and response bias in unilateral spatial neglect.

In some patients with unilateral spatial neglect, symptoms reflect impaired lateralized spatial attention and representation (perceptual bias) whereas in others the inability to respond to stimuli located in contralesional space (response bias). Here, we investigated whether prismatic adaptation (PA) and visual scanning training (VST) differentially affect perceptual and response bias and whether rehabilitation outcome depends on the type of bias underlying symptoms. Two groups of neglect patients in the subacute phase were evaluated before, immediately after, and two weeks following 10 days of PA (n = 9) or VST (n = 9). Standard neuropsychological tests (i.e., Behavioural Inattentional Test, Diller cancellation test, and Line Bisection test) were administered to assess neglect symptoms, while the Landmark task was used to disentangle perceptual and response biases. Performance on the Landmark task revealed that PA was more effective in improving the perceptual bias, while VST mainly modulated the response bias. Neuropsychological tests performance suggested that VST is better suited to modulate neglect in patients with response bias, while PA may be effective in patients with both types of bias. These findings may offer novel insights into the efficacy of PA and VST in the rehabilitation of perceptual and response biases in patients with neglect.

Manipulating topological Hall-like signatures by interface engineering in epitaxial ruthenate/manganite heterostructures.

Topologically protected non-trivial spin textures (e.g. skyrmions) give rise to a novel phenomenon called the topological Hall effect (THE) and have promising implications in future energy-efficient nanoelectronic and spintronic devices. Here, we have studied the Hall effect in SrRuO3/La0.42Ca0.58MnO3 (SRO/LCMO) bilayers. Our investigation suggests that pure SRO has hard and soft magnetic characteristics but the anomalous Hall effect (AHE) in SRO is governed by the high coercivity phase. We have shown that the proximity effect of a soft magnetic LCMO on SRO plays a critical role in interfacial magnetic coupling and transport properties in SRO. Upon reducing the SRO thickness in the bilayer, the proximity effect becomes the dominant feature, enhancing the magnitude and temperature range of THE-like signatures. The THE-like features in bilayers can be explained by a diffusive Berry phase transition model in the presence of an emergent magnetic state due to interface coupling. This work provides an alternative understanding of THE-like signatures and their manipulation in SRO-based heterostructures, bilayers and superlattices.

Anisotropic Properties of Epitaxial Ferroelectric Lead-Free 0.5[Ba(Ti0.8Zr0.2)O3]-0.5(Ba0.7Ca0.3)TiO3 Films.

As the energy demand is expected to double over the next 30 years, there has been a major initiative towards advancing the technology of both energy harvesting and storage for renewable energy. In this work, we explore a subset class of dielectrics for energy storage since ferroelectrics offer a unique combination of characteristics needed for energy storage devices. We investigate ferroelectric lead-free 0.5[Ba(Ti0.8Zr0.2)O3]-0.5(Ba0.7Ca0.3)TiO3 epitaxial thin films with different crystallographic orientations grown by pulsed laser deposition. We focus our attention on the influence of the crystallographic orientation on the microstructure, ferroelectric, and dielectric properties. Our results indicate an enhancement of the polarization and strong anisotropy in the dielectric response for the (001)-oriented film. The enhanced ferroelectric, energy storage, and dielectric properties of the (001)-oriented film is explained by the coexistence of orthorhombic-tetragonal phase, where the disordered local structure is in its free energy minimum.

Emergent Magnetism with Continuous Control in the Ultrahigh-Conductivity Layered Oxide PdCoO2.

The current challenge to realizing continuously tunable magnetism lies in our inability to systematically change properties, such as valence, spin, and orbital degrees of freedom, as well as crystallographic geometry. Here, we demonstrate that ferromagnetism can be externally turned on with the application of low-energy helium implantation and can be subsequently erased and returned to the pristine state via annealing. This high level of continuous control is made possible by targeting magnetic metastability in the ultrahigh-conductivity, nonmagnetic layered oxide PdCoO2 where local lattice distortions generated by helium implantation induce the emergence of a net moment on the surrounding transition metal octahedral sites. These highly localized moments communicate through the itinerant metal states, which trigger the onset of percolated long-range ferromagnetism. The ability to continuously tune competing interactions enables tailoring precise magnetic and magnetotransport responses in an ultrahigh-conductivity film and will be critical to applications across spintronics.

Hedonic and autonomic responses in promoting affective touch.

Interpersonal touch is intrinsically reciprocal since it entails a person promoting and another receiving the touch. While several studies have investigated the beneficial effects of receiving affective touch, the affective experience of caressing another individual remains largely unknown. Here, we investigated the hedonic and autonomic responses (skin conductance and heart rate) in the person promoting affective touch. We also examined whether interpersonal relationship, gender, and eye contact modulate these responses. As expected, caressing the partner was perceived as more pleasant than caressing a stranger, especially if the affective touch occurred together with mutual eye contact. Promoting affective touch to the partner also resulted in a decrease of both autonomic responses and anxiety levels, suggesting the occurrence of a calming effect. Additionally, these effects were more pronounced in females compared to males, indicating that hedonic and autonomic aspects of affective touch are modulated by both social relationship and gender. These findings show for the first time that caressing a beloved one is not only pleasant but also reduces autonomic responses and anxiety in the person promoting the touch. This might suggest that affective touch has an instrumental role for romantic partners in promoting and reinforcing their affective bonding.

Machine Learning-Enabled Superior Energy Storage in Ferroelectric Films with a Slush-Like Polar State.

Heterogeneities in structure and polarization have been employed to enhance the energy storage properties of ferroelectric films. The presence of nonpolar phases, however, weakens the net polarization. Here, we achieve a slush-like polar state with fine domains of different ferroelectric polar phases by narrowing the large combinatorial space of likely candidates using machine learning methods. The formation of the slush-like polar state at the nanoscale in cation-doped BaTiO3 films is simulated by phase field simulation and confirmed by aberration-corrected scanning transmission electron microscopy. The large polarization and the delayed polarization saturation lead to greatly enhanced energy density of 80 J/cm3 and transfer efficiency of 85% over a wide temperature range. Such a data-driven design recipe for a slush-like polar state is generally applicable to quickly optimize functionalities of ferroelectric materials.

Pain perception and physiological responses are modulated by active support from a romantic partner.

As social animals, humans are strongly affected by social bonds and interpersonal interactions. Proximity and social support from significant others may buffer the negative outcomes of a painful experience. Several studies have investigated the role of romantic partners' support in pain modulation, mostly focusing on tactile support and showing its effectiveness in reducing pain perception. Nevertheless, no study so far has investigated the role of supportive speaking on pain modulation, nor has compared the effects of a tactile and vocal support within the same couples. The present study directly compared for the first time the efficacy of mere presence (Passive Support) and different forms of active (Touch, Voice, Touch + Voice) support from a romantic partner during a painful experience in a naturalistic setting. We assessed pain modulation in 37 romantic couples via both subjective (self-reported ratings) and physiological (skin conductance) measurements. We found that all three types of active support were equally more effective than passive support in reducing the painful experience at both subjective and physiological levels; interestingly, our results suggest that supportive speaking can reduce pain perception with respect to passive support to a similar extent as tactile support does. Overall, this study highlights the relevance of an active support in reducing pain perception, with active types of support being more effective than passive support, regardless of its specific modality.

Beyond alpha-band: The neural correlate of creative thinking.

The compound nature of creativity entails the interplay of multiple cognitive processes, making it difficult to attribute creativity to a single neural signature. Divergent thinking paradigms, widely adopted to investigate creative production, have highlighted the key role of specific mental operations subserving creativity, such as inhibition of external stimuli, loose semantic associations, and mental imagery. Neurophysiological studies have typically shown a high alpha rhythm synchronization when individuals are engaged in creative ideation. Also, oculomotor activity and pupil diameter have been proposed as useful indicators of mental operations involved in such a thinking process. The goal of this study was to investigate whether beyond alpha-band activity other higher frequency bands, such as beta and gamma, may subserve divergent and convergent thinking and whether those could be associated with a different gaze bias and pupil response during ideas generation. Implementing a within-subjects design we collected behavioral measures, neural activity, gaze patterns, and pupil dilation while participants performed a revised version of the Alternative Uses Task, in which divergent thinking is contrasted to convergent thinking. As expected, participants took longer to generate creative ideas as compared to common ones. Interestingly, during divergent thinking participants displayed alpha synchronization along with beta and gamma desynchronization, more pronounced leftward gaze shift, and greater pupil dilation. During convergent thinking, an opposite pattern was observed: desynchronization in alpha and an increase in beta and gamma rhythm, along with a reduction of leftward gaze shift and greater pupil constriction. The present study uncovered specific neural dynamics and physiological patterns during idea generation, providing novel insight into the complex physiological signature of creative production.

Superconducting Fourfold Fe(Te,Se) Film on Sixfold Magnetic MnTe via Hybrid Symmetry Epitaxy.

Epitaxial Fe(Te,Se) thin films have been grown on various substrates but never been grown on magnetic layers. Here we report the epitaxial growth of fourfold Fe(Te,Se) film on a sixfold antiferromagnetic insulator, MnTe. The Fe(Te,Se)/MnTe heterostructure shows a clear superconducting transition at around 11 K, and the critical magnetic field measurement suggests the origin of the superconductivity to be bulk-like. Structural characterizations suggest that the uniaxial lattice match between Fe(Te,Se) and MnTe allows a hybrid symmetry epitaxy mode, which was recently discovered between Fe(Te,Se) and Bi2Te3. Furthermore, the Te/Fe flux ratio during deposition of the Fe(Te,Se) layer is found to be critical for its superconductivity. Now that superconducting Fe(Te,Se) can be grown on two related hexagonal platforms, Bi2Te3 and MnTe, this result opens a new possibility of combining topological superconductivity of Fe(Te,Se) with the rich physics in the intrinsic magnetic topological materials (MnTe)n(Bi2Te3)m family.

Development and Calibration of a Low-Cost, Piezoelectric Rainfall Sensor through Machine Learning.

In situ measurements of precipitation are typically obtained by tipping bucket or weighing rain gauges or by disdrometers using different measurement principles. One of the most critical aspects of their operational use is the calibration, which requires the characterization of instrument responses both in laboratory and in real conditions. Another important issue with in situ measurements is the coverage. Dense networks are desirable, but the installation and maintenance costs can be unaffordable with most of the commercial conventional devices. This work presents the development of a prototype of an impact rain gauge based on a very low-cost piezoelectric sensor. The sensor was developed by assembling off-the-shelf and reused components following an easy prototyping approach; the calibration of the relationship between the different properties of the voltage signal, as sampled by the rain drop impact, and rainfall intensity was established using machine-learning methods. The comparison with 1-minute rainfall obtained by a co-located commercial disdrometer highlights the fairly good performance of the low-cost sensor in monitoring and characterizing rainfall events.

High Entropy Oxide Relaxor Ferroelectrics.

Relaxor ferroelectrics are important in technological applications due to strong electromechanical response, energy storage capacity, electrocaloric effect, and pyroelectric energy conversion properties. Current efforts to discover and design materials in this class generally rely on substitutional doping as slight changes to local compositional order can significantly affect the Curie temperature, morphotropic phase boundary, and electromechanical responses. In this work, we demonstrate that moving to the strong limit of compositional complexity in an ABO3 perovskite allows stabilization of relaxor responses that do not rely on a single narrow phase transition region. Entropy-assisted synthesis approaches are utilized to synthesize single-crystal Ba(Ti0.2Sn0.2Zr0.2Hf0.2Nb0.2)O3 [Ba(5B)O] films. The high levels of configurational disorder present in this system are found to influence dielectric relaxation, phase transitions, nanopolar domain formation, and Curie temperature. Temperature-dependent dielectric, Raman spectroscopy, and second-harmonic generation measurements reveal multiple phase transitions, a high Curie temperature of 570 K, and the relaxor ferroelectric nature of Ba(5B)O films. The first-principles theory calculations are used to predict possible combinations of cations to design relaxor ferroelectrics and quantify the relative feasibility of synthesizing these highly disordered single-phase perovskite systems. The ability to stabilize single-phase perovskites with various cations on the B-sites offers possibilities for designing high-performance relaxor ferroelectric materials for piezoelectric, pyroelectric, and electrocaloric applications.

Designing Magnetism in High Entropy Oxides.

In magnetic systems, spin and exchange disorder can provide access to quantum criticality, frustration, and spin dynamics, but broad tunability of these responses and a deeper understanding of strong limit disorder are lacking. Here, it is demonstrated that high entropy oxides present a previously unexplored route to designing materials in which the presence of strong local compositional disorder may be exploited to generate tunable magnetic behaviors-from macroscopically ordered states to frustration-driven dynamic spin interactions. Single-crystal La(Cr0.2 Mn0.2 Fe0.2 Co0.2 Ni0.2 )O3 films are used as a model system hosting a magnetic sublattice with a high degree of microstate disorder in the form of site-to-site spin and exchange type inhomogeneity. A classical Heisenberg model simplified to represent the highest probability microstates well describes how compositionally disordered systems can paradoxically host magnetic uniformity and demonstrates a path toward continuous control over ordering types and critical temperatures. Model-predicted materials are synthesized and found to possess an incipient quantum critical point when magnetic ordering types are designed to be in direct competition, this leads to highly controllable exchange bias behaviors previously accessible only in intentionally designed bilayer heterojunctions.

Reversible Hydrogen-Induced Phase Transformations in La0.7Sr0.3MnO3 Thin Films Characterized by In Situ Neutron Reflectometry.

We report on the mechanism for hydrogen-induced topotactic phase transitions in perovskite (PV) oxides using La0.7Sr0.3MnO3 as a prototypical example. Hydrogenation starts with lattice expansion confirmed by X-ray diffraction (XRD). The strain- and oxygen-vacancy-mediated electron-phonon coupling in turn produces electronic structure changes that manifest through the appearance of a metal insulator transition accompanied by a sharp increase in resistivity. The ordering of initially randomly distributed oxygen vacancies produces a PV to brownmillerite phase (La0.7Sr0.3MnO2.5) transition. This phase transformation proceeds by the intercalation of oxygen vacancy planes confirmed by in situ XRD and neutron reflectometry (NR) measurements. Despite the prevailing picture that hydrogenation occurs by reaction with lattice oxygen, NR results are not consistent with deuterium (hydrogen) presence in the La0.7Sr0.3MnO3 lattice at steady state. The film can reach a highly oxygen-deficient La0.7Sr0.3MnO2.1 metastable state that is reversible to the as-grown composition simply by annealing in air. Theoretical calculations confirm that hydrogenation-induced oxygen vacancy formation is energetically favorable in La0.7Sr0.3MnO3. The hydrogenation-driven changes of the oxygen sublattice periodicity and the electrical and magnetic properties similar to interface effects induced by oxygen-deficient cap layers persist despite hydrogen not being present in the lattice.

Hybrid Symmetry Epitaxy of the Superconducting Fe(Te,Se) Film on a Topological Insulator.

It is challenging to grow an epitaxial 4-fold compound superconductor (SC) on a 6-fold topological insulator (TI) platform due to the stringent lattice-matching requirement. Here, we demonstrate that Fe(Te,Se) can grow epitaxially on a TI (Bi2Te3) layer due to accidental, uniaxial lattice match, which is dubbed as "hybrid symmetry epitaxy". This new growth mode is critical to stabilizing robust superconductivity with TC as high as 13 K. Furthermore, the superconductivity in this FeTe1-xSex/Bi2Te3 system survives in the Te-rich phase with Se content as low as x = 0.03 but vanishes at Se content above x = 0.56, exhibiting a phase diagram that is quite different from that of the conventional Fe(Te,Se) systems. This unique heterostructure platform that can be formed in both TI-on-SC and SC-on-TI sequences opens a route to unprecedented topological heterostructures.

Magnetic Texture in Insulating Single Crystal High Entropy Oxide Spinel Films.

Magnetic insulators are important materials for a range of next-generation memory and spintronic applications. Structural constraints in this class of devices generally require a clean heterointerface that allows effective magnetic coupling between the insulating layer and the conducting layer. However, there are relatively few examples of magnetic insulators that can be synthesized with surface qualities that would allow these smooth interfaces and precisely tuned interfacial magnetic exchange coupling, which might be applicable at room temperature. In this work, we demonstrate an example of how the configurational complexity in the magnetic insulator layer can be used to realize these properties. The entropy-assisted synthesis is used to create single-crystal (Mg0.2Ni0.2Fe0.2Co0.2Cu0.2)Fe2O4 films on substrates spanning a range of strain states. These films show smooth surfaces, high resistivity, and strong magnetic responses at room temperature. Local and global magnetic measurements further demonstrate how strain can be used to manipulate the magnetic texture and anisotropy. These findings provide insight into how precise magnetic responses can be designed using compositionally complex materials that may find application in next-generation magnetic devices.

External validation of the DIVA and DIVA3 clinical predictive rules to identify difficult intravenous access in paediatric patients.

BACKGROUND: Intravenous (IV) peripheral access is often a difficult procedure in the paediatric ED, causing pain and significant distress. Clinical prediction tools including reproducible variables have been developed to help clinicians identify children at risk of difficult IV access, likely to need additional resources/interventions to maximise success at first attempt. We aimed to externally validate the Difficult IntraVenous Access (DIVA) and DIVA3 scores developed for this purpose. METHODS: Cross-sectional study of children undergoing IV cannulation by nurses in a tertiary-care paediatric ED. Data were collected at the time of the procedure in a clinical report form. RESULTS: Of 440 children included (56.8% males; median age 4.7 years (IQR 1.5-9.5)), 23.4% had a difficult IV access (defined as requiring >1 attempt). Diagnostic accuracy measures for a DIVA cut-off ≥4 and their 95% CIs were sensitivity 24.3% (16.4% to 33.7%), specificity 92.6% (89.2% to 95.1%), positive and negative predictive value 50.0% (35.3% to 64.5%) and 80.0% (75.7% to 83.9%), respectively. The same measures for the DIVA3 were 22.3% (14.7% to 31.6%), 93.5% (90.3% to 95.9%), 51.1% (35.8% to 66.3%) and 79.8% (75.4% to 83.6%). The area under the receiver operating characteristic curve was 0.652 (95% CI 0.591 to 0.712) for the DIVA and 0.649 (95% CI 0.589 to 0.709) for the DIVA3 score. In patients with DIVA and DIVA3 <4, nurses' prediction of greater difficulty in IV placement and moderate/severe dehydration were common independent predictors of difficult IV at multivariate analysis. Only nurses' prediction of greater difficulty in IV placement were associated with higher odds of difficult cannulation for both DIVA/DIVA3 scores ≥4. CONCLUSION: We externally validated the DIVA and DIVA3 showing a similar accuracy compared with the DIVA derivation cohort and between DIVA and DIVA3. We identified factors that can help refine further the risk of difficult IV access and support decision making on the best strategy to maximise the chances of cannulation success on first attempt.