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The "lipid raft" hypothesis proposes that cell membranes contain distinct domains of varying lipid compositions, where "rafts" of ordered lipids and cholesterol coexist with disordered lipid regions. Experimental and theoretical phase diagrams of model membranes have revealed multiple coexisting phases. Molecular dynamics (MD) simulations can also capture spontaneous phase separation of bilayers. However, these methods merely determine the sign of the free energy change upon phase separation—whether or not it is favorable—but not the amplitude. Recently, we developed a workflow to compute the free energy of phase separation from MD simulations using the weighted ensemble method. However, while theoretical treatments generally focus on infinite systems and experimental measurements on mesoscopic to macroscopic systems, MD simulations are comparatively small. Therefore, if we are to put the results of these calculations into the appropriate context, we need to understand the effects the finite size of the simulation has on the computed free energy landscapes. In this study, we investigate this phenomenon by computing free energy profiles for a model phase-separating system as a function of system size, ranging from 324 to 10 110 lipids. The results suggest that, within the limits of statistical uncertainty, bulk-like behavior emerges once the systems contain roughly 4000 lipids. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are new class of organic porous materials with tunable pore size and low weight density, demonstrating remarkable potential applications in gas storage, gas separation, and catalysis. The inherent periodic porosity of COF monolayers (MLs) establishes anchoring sites for single atoms. Using first-principles calculations, we study the structural and electronic properties of atom-embedded C 6 N 6 and B 6 O 6 MLs. Subsequently, the intercalation of atoms between C 6 N 6 and B 6 O 6 bilayers (BLs) and their heterostructure (HTS) are investigated. Our findings show the significant effects of embedded atoms on the structural parameters of the host material. Notably, the Li atom anchors within the pore region of C 6 N 6 ML without forming bonds, while it establishes two σ bonds with O atoms in B 6 O 6 ML. The Cs atom forms six bonds in both MLs and resides between layers in BLs. In the HTS, the Cs atom forms six bonds with N atoms of the C 6 N 6 layer, positioning in the middle of the layers. Calculations reveal that Li and Cs atoms induce a red shift in energy, leading to a semiconductor–metal transition. Conversely, the insertion of an F atom induces a blue shift in energy, creating a midgap state at the Fermi energy. [ABSTRACT FROM AUTHOR]

We explore the existence of spin glass phase in FeCo/FePt bilayers arising due to disordered ferromagnet. The non-ergodic and highly degenerate landscape of the spin glass phase at low temperature explains the origin of complex magnetic texture in the FeCo/FePt system. Upon cooling the bilayered system, the magnetic texture undergoes spin freezing below 120 K as evident from the bifurcations in zero field cooling and field cooling magnetizations at low magnetic field as a manifestation of broken ergodicity. The uncompensated magnetic moments originating in the spin glass state result in slow time dynamics of thermoremanent magnetization. Consequently, the bilayers demonstrate an intriguing magnetic memory effect in which the magnetic state of the system could be retrieved upon isothermal ageing below 120 K after reversing the temperature cycle. Thermal treatment deteriorates the spin glass behaviour and shows a transition to strong ferromagnetic character in FeCo/FePt bilayers. [ABSTRACT FROM AUTHOR]

Environmental factors, including mechanical stress and surrounding lipids, can influence the response of GPCRs, such as the mechanosensitive angiotensin II type 1 receptor (AT1). To investigate the impact of these factors on AT1 activation, we developed a steered molecular dynamics simulations protocol based on quaternion formalism. In this protocol, a pulling force was applied to the N-terminus of transmembrane helix 6 (TM6) to induce the TM6 opening characteristic of activation. Subsequently, the simulations were continued without constraints to allow the receptor to relax around the novel TM6 conformation under different conditions. We analyzed the responses of AT1 to membrane stretching, modeled by applying surface tension, in different bilayers. In phosphocholine bilayers without surface tension, we could observe a transient atypical structure of AT1, with an outward TM7 conformation, at the beginning of the activation process. This atypical structure then evolved toward a pre-active structure with outward TM6 and inward TM7. Strikingly, the presence of anionic phosphoglycerol lipids and application of surface tension synergistically favored the atypical structure, which led to an increase in the cross-section area of the receptor intracellular domain. Lipid internalization and H-bonds between lipid heads and the receptor C-terminus increased in phosphoglycerol vs phosphocholine bilayers, but did not depend on surface tension. The difference in the cross-section area of the atypical and pre-active conformations makes the conformational transition sensitive to lateral pressure, and favors the atypical conformation upon surface tension. Anionic lipids act as allosteric modulators of the conformational transition, by stabilizing the atypical conformation. These findings contribute to decipher the mechanisms underlying AT1 activation, highlighting the influence of environmental factors on GPCR responses. Moreover, our results reveal the existence of intermediary conformations that depend on receptor environment and could be targeted in drug design efforts. Author summary: Mechanical forces play a critical role in the physiopathology of the cardiovascular system. The angiotensin II type 1 receptor (AT1) is a key regulator of cardiovascular functions. This receptor acts as a mechanosensor, capable of being activated by mechanical forces, although the underlying mechanism remains poorly understood. In this study, we investigate the relationship between environmental conditions, specifically mechanical stress and surrounding lipids, and the activation mechanism of AT1. To gain a deeper understanding of this complex interplay, we utilize steered molecular dynamics simulations based on quaternion formalism. Our study reveals an atypical conformation of the AT1 receptor which serves as a transient intermediate in the receptor activation pathway. This atypical conformation of AT1 is stabilized by a compelling synergy between mechanical stress (represented by surface tension) and anionic lipids (represented by phosphoglycerol lipids). This finding strongly suggests that specific lipids may play a crucial role in transmitting mechanical signals to the AT1 receptor. These insights will contribute to understand the development of diseases such as hypertension, where AT1 signaling is impaired in response to mechanical stress, and their link with the lipidome of the cardiovascular cell membranes. They can also help drug design targeted toward distinct conformations of AT1 to induce specific pathways. [ABSTRACT FROM AUTHOR]

In the present work the atomic, electronic and optical properties of two-dimensional graphene, borophene, and boron carbide heterojunction bilayer systems (Graphene–BC3, Graphene–Borophene and Graphene–B4C3) as well as their constituent monolayers are investigated on the basis of first-principles calculations using the HSE06 hybrid functional. Our calculations show that while borophene is metallic, both monolayer BC3 and B4C3 are indirect semiconductors, with band-gaps of 1.822 eV and 2.381 eV as obtained using HSE06. The Graphene–BC3 and Graphene–B4C3 bilayer heterojunction systems maintain the Dirac point-like character of graphene at the K-point with the opening of a very small gap (20–50 meV) and are essentially semi-metals, while Graphene–Borophene is metallic. All bilayer heterostructure systems possess absorbance in the visible region where the resonance frequency and resonance absorption peak intensity vary between structures. Remarkably, all heterojunctions support plasmons within the range 16.5–18.5 eV, while Graphene–B4C3 and Graphene–Borophene exhibit a π -type plasmon within the region 4–6 eV, with the latter possessing an additional plasmon at the lower energy of 1.5–3 eV. The dielectric tensor for Graphene–B4C3 exhibits complex off-diagonal elements due to the lower P3 space group symmetry indicating it has anisotropic dielectric properties and could exhibit optically active (chiral) effects. Our study shows that the two-dimensional heterostructures have desirable optical properties broadening the potential applications of the constituent monolayers. [ABSTRACT FROM AUTHOR]

We report the observation of an electric field in twisted-bilayer molybdenum disulfide (MoS2) and elucidate its correlation with local polar domains using four-dimensional scanning transmission electron microscopy (4D-STEM) and first-principles calculations. We reveal the emergence of in-plane topological vortices within the periodic moiré patterns for both commensurate structures at small twist angles and the incommensurate quasicrystal structure that occurs at a 30° twist. The large-angle twist leads to mosaic chiral vortex patterns with tunable characteristics. A twisted quasicrystal bilayer, characterized by its 12-fold rotational symmetry, hosts complex vortex patterns and can be manipulated by picometer-scale interlayer displacement. Our findings highlight that twisting 2D bilayers is a versatile strategy for tailoring local electric polar vortices. [ABSTRACT FROM AUTHOR]

Mitochondrial fusion requires the sequential merger of four bilayers to two. The outer-membrane solute carrier family 25 member (SLC25A46) interacts with both the outer and inner membrane dynamin family GTPases mitofusin 1/2 and optic atrophy 1 (Opa1). While SLC25A46 levels are known to affect mitochondrial morphology, how SLC25A46 interacts with mitofusin 1/2 and Opa1 to regulate membrane fusion is not understood. In this study, we use crosslinking mass spectrometry and AlphaFold 2 modeling to identify interfaces mediating an SLC25A46 interaction with Opa1 and Mfn2. We reveal that the bundle signaling element of Opa1 interacts with SLC25A46, and present evidence of an Mfn2 interaction involving the SLC25A46 cytosolic face. We validate these newly identified interaction interfaces and show that they play a role in mitochondrial network maintenance. [ABSTRACT FROM AUTHOR]

Detection of ultralow magnetic field requires a magnetic sensor with high sensitivity and a low noise level. In this work, we used the Co20Fe60B20/Ti/Co20Fe60B20 magnetically coupled multilayer as the core structure of an anomalous Hall sensor. We adjusted the thickness of the Ti interlayer to modify its perpendicular magnetic anisotropy and interlayer magnetic coupling, thereby improving the sensitivity of the anomalous Hall sensor. Through the investigation of magnetic field response and noise properties of devices with different Ti thicknesses, the highest sensitivity of 34 803 Ω/T and the best magnetic field detectivity of 4.6 nT/ Hz at 1 Hz were achieved with a Ti thickness of 2.0 nm at room temperature. This anomalous Hall sensor has both ultrahigh sensitivity and magnetic field detectivity, making it a good candidate for applications in detecting weak magnetic fields. [ABSTRACT FROM AUTHOR]

Novel optical sources require fast decay rates, making hyperbolic metamaterials (HMMs) an increasingly attractive option. HMMs are well‐known for their remarkable anisotropy, and leverage hyperbolic dispersion to enhance the decay rate of a fluorophore placed on top of them. This study tackles the complex task of embedding a fluorophore into an HMM, successfully overcoming challenges related to surface roughness, thickness imperfections, and layer washing effects. Specifically, CsPbBr3 perovskite nanocrystals (NCs)‐based HMM are fabricated, by alternating silver/nanocrystals (Ag/NCs) layers. Through a systematic investigation of the photophysical response following the deposition of each bilayer, compelling evidence of the achievement of hyperbolic dispersion is provided. Specifically, the impact of "high‐k" modes is isolated, which is distinctive to the HMM architecture. Therefore, the longstanding debate regarding the number of bilayers needed to achieve hyperbolic dispersion is conclusively resolved. The research demonstrates a nearly twofold increase in the decay rate and a threefold enhancement in photoluminescence intensity. These findings are further supported by theoretical Purcell factor calculations. This study marks a pioneering advancement in the field of bulk dye‐embedded HMMs, laying the groundwork for the development of advanced optical sources such as "resonant gain HMMs". [ABSTRACT FROM AUTHOR]

We have investigated the Ni magnetic alignment when deposited on the CrN (111) magnetic surface and the possible growth of NiN and Ni4N on this surface using first principles calculations. The results revealed that when Ni substituted the Cr atoms of the outermost layer, a switching in the magnetic arrangement, from ferromagnetic to antiferromagnetic, takes place. We have used the surface formation energy (SFE) formalism to establish the thermodynamic stability to study the growth of these nickel nitrides. According to the results, NiN growth yields the formation of only 2 bilayers under N-rich conditions; in contrast, Ni4N may grow on the CrN (111) substrate. To confirm the stability, ab initio molecular dynamics (AIDM) calculations were performed at 80 K and 300 K; moreover, different strains have been considered in the studies. Our results suggest that the Ni4N (111) surface may form with a strain substrate up to 6% at low temperatures and below; the compound is stable at room temperature. Beyond this strain, the structure showed a non-crystalline array. In addition, the SFE demonstrated that the N-terminated surface is the most stable configuration under Ni-rich conditions, for example, at 20% N2 flux. These facts agree well with the experimental data. The magnetic anisotropic energy (MAE) of the NiN structure showed that the Ni spins are pinned to the easy magnetization axis of the CrN (111) surface, and its electronic properties exhibit a metallic character. [ABSTRACT FROM AUTHOR]

Cell membranes are crucial elements in living organisms, serving as protective barriers and providing structural support for cells. They regulate numerous exchange and communication processes between cells and their environment, including interactions with other cells, tissues, ions, xenobiotics, and drugs. However, the complexity and heterogeneity of cell membranes—comprising two asymmetric layers with varying compositions across different cell types and states (e.g., healthy vs. diseased)—along with the challenges of manipulating real cell membranes represent significant obstacles for in vivo studies. To address these challenges, researchers have developed various methodologies to create model cell membranes or membrane fragments, including mono- or bilayers organized in planar systems. These models facilitate fundamental studies on membrane component interactions as well as the interactions of membrane components with external agents, such as drugs, nanoparticles (NPs), or biomarkers. The applications of model cell membranes have extended beyond basic research, encompassing areas such as biosensing and nanoparticle camouflage to evade immune detection. In this review, we highlight advancements in the engineering of planar model cell membranes, focusing on the nanoarchitectonic tools used for their fabrication. We also discuss approaches for incorporating challenging materials, such as proteins and enzymes, into these models. Finally, we present our view on future perspectives in the field of planar model cell membranes. [ABSTRACT FROM AUTHOR]

Proximity effects allow for the adjustment of magnetic properties in a physically elegant way. If two thin ferromagnetic (FM) films are brought into contact, electronic coupling alters their magnetic exchange interaction at their interface. For a low- T C rare-earth FM coupled to a 3d transition metal FM, even room temperature magnetism is within reach. In addition, magnetic proximity coupling is particularly promising for increasing the magnetic order of metastable materials such as europium monoxide (EuO) beyond their bulk T C , since neither the stoichiometry nor the insulating properties are modified. We investigate the magnetic proximity effect at Fe/EuO and Co/EuO interfaces using hard X-ray photoelectron spectroscopy. By exciting the FM layers with circularly polarized light, magnetic dichroism is observed in angular dependence on the photoemission geometry. In this way, the depth-dependence of the magnetic signal is determined element-specifically for the EuO and 3d FM parts of the bilayers. In connection with atomistic spin dynamics simulations, the thickness of the EuO layer is found to be crucial, indicating that the observed antiferromagnetic proximity coupling is a short-ranged and genuine interface phenomenon. This fact turns the bilayer into a strong synthetic ferrimagnet. The increase in magnetic order in EuO occurs in a finite spatial range and is therefore particularly strong in the 2D limit—a counterintuitive but very useful phenomenon for spin-based device applications. [ABSTRACT FROM AUTHOR]

Layer-by-layer (LbL) assembly methods through alternative dipping processes were used to prepare hybrid nanoassemblies of 5 nm ZnO nanoparticles (ZnONPs) with catechol-functionalized polycyclosiloxane (CFPS60, 51.9 mol% catechol content). ZnONPs were assembled on solid substrates regularly and firmly through interactions with 4 nm-thick CFPS60, proved using UV-vis absorption measurements, atomic force microscopy and peel-off test. ZnONPs exhibited yellow photoluminescence (PL) in CFPS60/ZnONPs films, and the PL intensity increased notably as the number of bilayers increased. The work demonstrates that CFPS60 has a good hybrid nanoassembly formation capability, which is promising for next-generation optoelectronic device applications. [ABSTRACT FROM AUTHOR]

There is a growing interest in mixing spintronics and superconductivity to develop original energy-efficient nonvolatile memory and logic devices. Research works conducted so far have mostly focused on superconductor with critical temperature Tc lower than 10 K. Here, we report on the growth and characterization of MgB2/Ni80Fe20 and MgB2/Co bilayers, where Tc of the MgB2 layer is of the order of 30 K. Ferromagnetic resonance was undertaken to analyze the spin pumping into MgB2. The larger magnetization at saturation in Co, as compared to Ni80Fe20, induces a smaller spin pumping contribution to the damping when MgB2 is normal. A spin pumping reduction was observed for both bilayers when MgB2 becomes superconductor and is attributed to the opening of the superconducting gap. The present results show that MgB2 thin films could be suitable to implement superconducting spintronic at 30 K, which is not only relevant for future technological development but also relaxes experimental constraints related to low-temperature investigations. [ABSTRACT FROM AUTHOR]

We studied the interfacial spin Hall magnetotransport in the Tb3Fe5O12 (TbIG)/Pt system across a non-magnetic [Y3Al5O12 (YAG) and Gd3Ga5O12 (GGG)] spacer with garnet structure. TbIG (30 nm)/spacer samples were grown on single-crystal (GGG) (111) substrates by pulsed laser deposition before 5 nm of Pt was sputtered on the samples and patterned into Hall bars. The YAG spacer thickness (tYAG) dependences of anomalous Hall effect resistance (RAHE) indicated no significant change on the magnetization compensation temperature of TbIG. Hysteretic RAHE loops were observed at low magnetic fields, but with reducing magnitude as tYAG thickness increases. A crossover of the RAHE sign was observed at temperatures below the compensation temperature, which decreased sharply from 135 to 34 K as tYAG increased from 0 to 1 nm. We attributed this to the strong dependence of the magnetic proximity effect toward the YAG insertion in the TbIG/Pt interface. Replacement of the YAG spacer with GGG showed significant impact on the RAHE behavior. No obvious RAHE-H loops were observed in the TbIG/Pt sample inserted with 0.5 nm GGG spacer, which could be linked to the strong magnetic contribution of the Gd ions. This work highlights the tunability of interfacial transport behavior in iron garnet/heavy metal systems through ultrathin spacers, providing guidance for the interfacial design of spintronic devices. [ABSTRACT FROM AUTHOR]

Here, we show that the ferro(para)magnetic and non-collinear antiferromagnetic interfaces contribute to oscillating signals observed in the magnetoresistance. We associate the effect with the fact that the spins on the surface of IrMn 3 produce instability in the surface magnetoresistance of the material, which is sensitive to the magnetic field. We carried out experiments using bilayers of IrMn 3 under permalloy (Py) and IrMn 3 under platinum (Pt). The oscillations were intensely evident at the Py/IrMn 3 interface and less explicit at the Pt/IrMn 3 interface. We carried out the experiments using pulsed current, with a square pulse width of 1 μ s and amplitudes of I AC = 20 μ A to 20 mA. The oscillating signals are proportional to the crystallographic direction of the material, the ferromagnetism of the material adjacent to IrMn 3 , and sensitive to the amplitude of the pulsed current. We believe that observation is a way of transmitting encoded information through magnetoresistance. [ABSTRACT FROM AUTHOR]

Nonreciprocal magnetotransport is one of the central topics in spintronics because of its importance for electrically probing magnetic information. Among numerous electrical probes used to read magnetic orders, unidirectional magnetoresistance (UMR), characterized by sign changes upon reversal of either current or magnetization, is currently a matter of great interest and has been identified in various spin–orbit-coupled bilayer systems composed of an (anti)ferromagnetic layer and a nonmagnetic layer with strong spin Hall effect. A recent theoretical work predicts that a spin-anomalous-Hall (SAH) UMR in those metallic conducting bilayers can originate from the spin-anomalous-Hall effect of the ferromagnetic layer and the structural inversion asymmetry. However, this type of UMR has not been reported experimentally. Here, we give the experimental evidence of spin-anomalous-Hall UMR in the light-metal/ferromagnetic-metal Cu/Co bilayers, where the emergence of net nonequilibrium spin density is attributed to the interfacial spin leakage asymmetry due to the spin memory loss effect at the Cu/Co interface and multiple spin reflections. We also show a highly tunable UMR in the Cu/Co/CuOx trilayer by varying the Cu thickness, which is due to the competition between the orbital Rashba effect in Co/CuOx and the spin-anomalous-Hall effect in Cu/Co. Our work widens the material choice for UMR device applications and provides an alternative approach to detect in-plane magnetization without an external spin polarizer. [ABSTRACT FROM AUTHOR]

Composition and morphology of two types of bilayers of plasma‐enhanced chemical vapor deposition hydrogened silicon nitride (SiNx:H) and polyimide (PI), as effcient barrier against moisture in SiC‐based power devices, are investigated. Two types of silicon nitrides are obtained by changing the flow ratios of the SiH4 and NH3 precursors. Rutherford Backscatterered analyses show that the Si/N ratio varies from 0.6 to 0.8. Elastic recoil detection analyses show that the sample with higher nitrogen content has a higher total bound hydrogen content of 7.8 × 1017 cm−2 with respect to the 7.1 × 1017 cm−2. Fourier‐transform infrared spectroscopy characterizations show Si–H group concentrations of 0.96 × 1017 and 6.86 × 1017 cm−2 and NH groups of 4.82 × 1017 and 2.28 × 1017 cm−2, respectively. Silicon nitride films with higher concentration of N–H groups show higher reactivity and permeability to water, making them less effective as a barrier layer. Atomic force microscopy analyses of a PI layer deposited on the nitride layer, SiNx:H/PI show for both type of samples a similar roughness, indicating planarization that can increase the adhesion of SiNx:H/PI and resistance to moisture. The delamination mechanism of the bilayer under pressure pot test conditions is proposed. [ABSTRACT FROM AUTHOR]

Poly (N-vinylcaprolactam) (PNVCL) and poly (N-isopropylacrylamide) (PNIPAm) are two popular negatively temperature-responsive hydrogels, due to their biocompatibility, softness, hydrophilicity, superabsorbency, viscoelasticity, and near-physiological lower critical solution temperature (LCST). These characteristics make them ideal for biomedical applications. When combined with other materials, hydrogel expansion induces the morphing of the assembly due to internal stress differences. Our recent developments in NVCL hydrogel, enhanced by nanoclay incorporation, have driven us to the creation of a bilayer structure to study its shapeshifting response across various temperatures. This study focused on the bending behaviour of bilayer samples composed of an active hydrogel layer and a passive non-swellable layer. Using photopolymerisation, circular discs and rectangular bilayer samples of varying sizes were fabricated. Homogeneous circular samples demonstrated that hydrogel density increased proportionally with temperature, with the swelling ratio exhibiting two distinct rates of change below and above its LCST. In bilayer samples, the volume of the passive layer influenced bending, and its optimal volume was identified. The investigation revealed that geometry affected the overall bending effect due to changes in the passive layer stiffness. Lastly, a temperature-responsive gripper capable of picking up objects several times its own weight was demonstrated, highlighting the potential of NVCL hydrogels as bioactuators for minimally invasive surgery. [ABSTRACT FROM AUTHOR]

[Display omitted] The friction and interfacial nanostructure of a water-in-surface-active ionic liquid mixture, 1.6 M 1-butyl-3-methylimidazolium 1,4-bis-2-ethylhexylsulfosuccinate ([BMIm][AOT]), can be tuned by applying potential on Au(1 1 1) and stainless steel. Atomic force microscopy (AFM) was used to examine the friction and interfacial nanostructure of 1.6 M [BMIm][AOT] on Au(1 1 1) and stainless steel at different potentials. Superlubricity (vanishing friction) is observed for both surfaces at OCP+1.0 V up to a surface-dependent critical normal force due to [AOT]− bilayers adsorbing strongly to the positively charged surface thus allowing AFM tip to slide over solution-facing hydrated anion charged groups. High-resolution AFM imaging reveals ripple-like features within near-surface layers, with the smallest amplitudes at OCP+1 V, indicating the highest structural stability and resistance to thermal fluctuations due to highly ordered boundary [AOT]− bilayers templating robust near-surface layers. Exceeding the critical normal force at OCP+1.0 V causes the AFM tip to penetrate the hydrated [AOT]− layer and slide over alkyl chains, increasing friction. At OCP and OCP-1.0 V, higher friction correlates with more pronounced ripples, attributed to the rougher templating [BMIm]+ boundary layer. Kinetic experiments show that switching from OCP-1.0 V to OCP+1.0 V achieves superlubricity within 15 s, enabling real-time friction control. [ABSTRACT FROM AUTHOR]

We investigate the relationships between various magnetic and spintronic properties within AuPt/ferromagnet (FM) bilayers (FM = CoFe, CoFeB, Py, and Co). A linear correlation between the volume and surface magnetic anisotropies is identified, potentially influenced by the magnetoelastic effect. The FM thickness dependence of the magnetic damping indicates that spin-memory loss due to the interfacial spin–orbit coupling (ISOC) and spin pumping to the heavy-metal layer contribute little to the damping. Instead, a notable contribution from two magnon scattering to the damping is recognized in AuPt/(Co, CoFe, CoFeB) bilayers, possibly originating from a magnetic inhomogeneity due to the ISOC. In addition, in contrast to the magnetic damping, spin–orbit-torque efficiencies are unlikely related to the ISOC in AuPt/FM systems. This work offers valuable insights into the correlations among magnetic and spintronic parameters arising from the interfaces, ultimately aiding in the advancement of magnetic memory and information processing systems. [ABSTRACT FROM AUTHOR]

The ongoing efforts to optimize rechargeable Li-ion batteries led to the interest in intercalation of nanoscale layered compounds, including bilayer graphene. Its lithium intercalation has been demonstrated recently but the mechanisms underpinning the storage capacity remain poorly understood. Here, using magnetotransport measurements, we report in-operando intercalation dynamics of bilayer graphene. Unexpectedly, we find four distinct intercalation stages that correspond to well-defined Li-ion densities. Transitions between the stages occur rapidly (within 1 sec) over the entire device area. We refer to these stages as 'in-plane', with no in-plane analogues in bulk graphite. The fully intercalated bilayers represent a stoichiometric compound C14LiC14 with a Li density of ∼2.7·1014 cm−2, notably lower than fully intercalated graphite. Combining the experimental findings and DFT calculations, we show that the critical step in bilayer intercalation is a transition from AB to AA stacking which occurs at a density of ∼0.9·1014 cm−2. Our findings reveal the mechanism and limits for electrochemical intercalation of bilayer graphene and suggest possible avenues for increasing the Li storage capacity. Lithium-ion intercalation of bilayer graphene is shown to proceed via four distinct stages corresponding to different ordered in-plane arrangements of Li ions, commensurate with the underlying graphene lattices in both AA and AB stacking configurations. [ABSTRACT FROM AUTHOR]

The group of moiré graphene superconductors keeps growing, and by now it contains twisted graphene multilayers as well as untwisted stacks. We analyze here the contribution of long-range charge fluctuations in the superconductivity of twisted double bilayers and helical trilayers, and compare the results to twisted bilayer graphene. A diagrammatic approach which depends on a few, well-known parameters is used. We find that the critical temperature and the order parameter differ significantly between twisted double bilayers and helical trilayers on one hand, and twisted bilayer graphene on the other. This trend, consistent with experiments, can be associated with the role played by moiré Umklapp processes in the different systems. [ABSTRACT FROM AUTHOR]

We explore the phase behavior of lipid bilayers containing SOPC (1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine) with various molar concentrations (0 mol%, 10 mol% and 30 mol%) of cholesterol. To this end, we performed extensive atomistic molecular dynamics simulations in conjunction with the Slipids force field with optimized parameters for the headgroups of phospholipids. We computed thermodynamic and structural quantities describing the ordering of the tails, the mobility of the heads and the arrangement of the lipids in the bilayers. We analyzed the behavior of the named quantities over the temperature range between 271 K and 283 K, where the experimentally determined melting temperature, T m = 279 K, lies, as well as at 400 K, which is used as a reference temperature. The obtained results are compared to available experimental data along with the outcome from molecular dynamics simulations of similar phospholipids containing different amounts of cholesterol. In the temperature interval of interest, we found evidence of the occurrence of a thermal-driven phase transition (melting) in both the pure system and the one with the lower concentration of cholesterol, while in the remaining system, the higher amount of cholesterol in the bilayer smears out the transitional behavior. Thus, we demonstrate the ability of the Slipids force field to predict the phase behavior of bilayers of SOPC and SOPC mixed with cholesterol. [ABSTRACT FROM AUTHOR]

Plasmonic applications have traditionally relied on noble metals such as gold (Au) and silver (Ag) for their excellent plasmonic performance in the visible and near-infrared spectrum. However, these metals are costly, scarce, and have limitations such as low stability (Ag) and interband transition losses, which restrict their spectral range. To address these issues, alternative plasmonic materials have been explored. One such material is aluminum (Al), which is inexpensive, abundant, and exhibits remarkable plasmonic properties in the UV region as well as wide tunability. Al is also compatible with complementary metal–oxide semiconductor (CMOS) fabrication processes and is very stable due to its ultrathin native oxide layer. Alloying different metals can combine their advantageous properties, resulting in enhanced tunable optical characteristics. This study investigates the LSPR properties of AgAl alloy nanoparticles grown after the annealing of precursor AgAl bilayer films. Interestingly, LSPRs were also observed in some cases for the as-deposited bilayers. The experimental results were complemented with simulations conducted via the rigorous coupled-wave analysis (RCWA) method. The investigated materials could be potentially useful for applications in energy harvesting or color printing. [ABSTRACT FROM AUTHOR]

Despite the discovery of multiple intrinsic magnetic topological insulators in recent years the observation of Chern insulators is still restricted to very low temperatures due to the negligible charge gaps. Here, we uncover the potential of heavy transition-metal compounds for realizing a collinear antiferromagnetic Chern insulator (AFCI) with a charge gap as large as 300 meV. Our analysis relies on the Kane-Mele-Kondo model with a ferromagnetic Hund coupling J H between the spins of itinerant electrons and the localized spins of size S. We show that a spin-orbit coupling λ SO ≳ 0.03 t , where t is the nearest-neighbor hopping element, is already large enough to stabilize an AFCI provided the alternating sublattice potential δ is in the range δ ≈ S J H . We establish a remarkable increase in the charge gap upon increasing λ SO in the AFCI phase. Using our results we explain the collinear AFCI recently found in monolayers of CrO and MoO with charge gaps of 1 and 50 meV , respectively. In addition, we propose bilayers of heavy transition-metal oxides of perovskite structure as candidates to realize a room-temperature AFCI if grown along the [111] direction and subjected to a perpendicular electric field. [ABSTRACT FROM AUTHOR]

The ground state of correlated electrons in complex oxide films can be controlled by applying epitaxial strain, offering the potential to produce unexpected phenomena applicable to modern spintronic devices. In this study, we demonstrate that substrate-induced strain strongly affects the coupling mode of interfacial magnetic moments in a ferromagnetic (FM)/antiferromagnetic (AFM) system. In an epitaxial bilayer comprising AFM LaFeO3 (LFO) and FM La0.7Sr0.3MnO3 (LSMO), samples grown on a LaAlO3 (LAO) substrate exhibit a larger exchange bias field than those grown on a SrTiO3 substrate. Our results indicate a transition in the alignment of magnetic moments from perpendicular to collinear due to the large compressive strain exerted by the LAO substrate. Collinear magnetic moments at the LSMO/LFO interface generate strong exchange coupling, leading to a considerable exchange bias effect. Thus, our findings provide a method for tailoring and manipulating the orientations of magnetic moments at the FM/AFM heterogeneous interface using strain engineering, thereby augmenting methods for exchange bias generation. [ABSTRACT FROM AUTHOR]

Spin-torque ferromagnetic resonance (ST-FMR) has been widely used for measuring damping-like spin–orbit torques in magnetic bilayers. Typically, the ratio between the damping-like and field-like spin–orbit torques are extrapolated based on the ferromagnetic resonance line shapes. However, when the field-like spin–orbit torque is unknown, the line shape analysis may lead to errors in extrapolating the damping-like spin–orbit torque. Here, we propose a modified version of the ST-FMR that allows extrapolation of both damping-like and field-like torques independently. By introducing an alternating current to the sample, the RF impedance is modulated, allowing detection via the reflected microwave. We show that the extrapolated field-like and damping-like torques in Py/Pt samples are consistent with the technique measuring current-induced linewidth and resonance field change but have much better signal-to-noise ratio. Our proposed method paves a way for more accurate measurement of spin–orbit torques. [ABSTRACT FROM AUTHOR]

While many researchers have focused on the interfacial Rashba effect, bulk Rashba materials have received considerable interest due to their potential to enhance spin–orbit torque (SOT). By utilizing GeTe as a bulk Rashba material in the role of a spin–orbit channel, GeTe/Ni81Fe19 and GeTe/Co40Fe40B20 bilayers are fabricated, and SOTs are investigated using the spin torque ferromagnetic (FM) resonance technique. In this method, damping‐like and field‐like SOTs are extracted individually, excluding thermal effects. Upon analyzing the data, a remarkable field‐like SOT efficiency of 0.40 is obtained from the GeTe/Ni81Fe19 system. This high efficiency is attributed to the enhancement of interfacial spin–orbit coupling through the bulk Rashba effect of the GeTe channel. Moreover, noticeable distinctions in SOTs are observed between the Co40Fe40B20 and Ni81Fe19 interfaces, underscoring the importance of selecting the appropriate FM layer for optimizing SOT efficiency. This study highlights the promising potential of bulk Rashba materials like GeTe in advancing SOT‐based devices. [ABSTRACT FROM AUTHOR]

When developing fluorescent membrane probes, we naturally tend to focus on the fluorophore itself. In this study, we show that sometimes it can be beneficial to shift attention from the center to the periphery, to maximize multiple interfacing with complex changing environments. Palmitylation for hydrophobic interfacing and glutamate dendrons for hydrophilic interfacing are combined to improve the performance of fluorescent flipper probes. We show that to increase performance in membranes, solubility in water is important, and to increase solubility in water, we increase the hydrophobicity of the flipper probe. These seemingly paradoxical measures are taken to satisfy the Israelachvili rules. They state that only inverted cone amphiphiles form soluble micelles in water, while inverted micelles from cone shaped amphiphiles precipitate into hexagonal 1 supramolecular polymers, and the intermediate cylindrical amphiphiles show intermediate behavior dominated by bilayers and lamellar precipitates. The normal micelles obtained from inverted cone flipper amphiphiles prevent precipitation and prepare for efficient transfer into the lipid bilayer membranes. The results are flippers that break all records set by the 2016 original with regard to effective brightness, responsiveness to membrane order, anchoring in disordered membranes, partitioning into membranes of high order, and stable labeling of membranes of interest. The lessons learned confirm the obvious: The Israelachvili rules apply also to fluorescent membrane probes. They promise literally bright perspectives for fluorescent membrane probes. [ABSTRACT FROM AUTHOR]

We report the observation of unidirectional magnetoresistance (UMR) in the ferrimagnetic insulator CoFe2O4(CFO)/Pt heterostructures, which stem from the giant interfacial Rashba–Edelstein effect. Furthermore, UMR has been found to show sign reversal and amplitude enhancement characteristics with decrease in temperature. We have ascribed it to the modulated distortion of Fermi contours due to pronounced spin canting at low temperatures. The presence of spin canting induced interfacial magnetic state has also been demonstrated by spin Hall magnetoresistance in CFO/Pt/Co/Al2O3 films. Our work reveals the interfacial magnetic state modulated UMR in CFO/Pt bilayers, thereby paving the way for extending its applications in ferrimagnet-based spintronic devices. [ABSTRACT FROM AUTHOR]

Integral membrane proteins (IMPs) constitute a large fraction of organismal proteomes, playing fundamental roles in physiology and disease. Despite their importance, the mechanisms underlying dynamic features of IMPs, such as anomalous diffusion, protein-protein interactions, and protein clustering, remain largely unknown due to the high complexity of cell membrane environments. Available methods for in vitro studies are insufficient to study IMP dynamics systematically. This publication introduces the freestanding bilayer microscope (FBM), which combines the advantages of freestanding bilayers with single-particle tracking. The FBM, based on planar lipid bilayers, enables the study of IMP dynamics with single-molecule resolution and unconstrained diffusion. This paper benchmarks the FBM against total internal reflection fluorescence imaging on supported bilayers and is used here to estimate ion channel open probability and to examine the diffusion behavior of an ion channel in phase-separated bilayers. The FBM emerges as a powerful tool to examine membrane protein/lipid organization and dynamics to understand cell membrane processes. [ABSTRACT FROM AUTHOR]

The combination of metallicity and ferroelectricity challenges conventional understanding, creating opportunities for advanced electronic materials and devices. This breakthrough is particularly notable, as metallicity and ferroelectricity have traditionally been considered mutually exclusive physical properties. In this work, starting with non-polar metallic single layers, we propose a design scheme for designing two-dimensional (2D) ferroelectric metals (FEMs) based on van der Waals interactions. By first-principles calculations, we also substantiate the feasibility of the design scheme in materials such as FeSe and H-MnTe2. Notably, this scheme unveils metallic ferroelectricity, characterized by reversing polarization through interlayer sliding. Furthermore, these systems exhibit a coexistence of inherent magnetism and sliding ferroelectricity. The investigated design scheme and observed phenomena have broad applicability across 2D materials. Our results not only advance research in 2D FEMs but also enhance the understanding of coupled physical phenomena in 2D lattices. [ABSTRACT FROM AUTHOR]

Transition-edge sensor (TES) microcalorimeters are advanced cryogenic detectors that use a superconducting film for particle or photon detection. We are establishing a new production line for TES detectors to serve as cryogenic anticoincidence (i.e., veto) devices. These detectors are made with a superconducting bilayer of titanium (Ti) and gold (Au) thin films deposited via electron beam evaporation in a high vacuum condition on a monocrystalline silicon substrate. In this work, we report on the development of such sensors, aiming to achieve stable sensing performance despite the effects of aging. For this purpose, patterned and non-patterned Ti/Au bilayer samples with varying geometries and thicknesses were fabricated using microfabrication technology. To characterize the detectors, we present and discuss initial results from repeated resistance–temperature (R–T) measurements over time, conducted on different samples, thereby augmenting existing literature data. Additionally, we present a discussion of the sensor's degradation over time due to aging effects and test a potential remedy based on an easy annealing procedure. In our opinion, this work establishes the groundwork for our new TES detector production line. [ABSTRACT FROM AUTHOR]

In this study, we demonstrate the fabrication of polymersomes, protein-blended polymersomes, and polymeric microcapsules using droplet microfluidics. Polymersomes with uniform, single bilayers and controlled diameters are assembled from water-in-oil-in-water double-emulsion droplets. This technique relies on adjusting the interfacial energies of the droplet to completely separate the polymer-stabilized inner core from the oil shell. Protein-blended polymersomes are prepared by dissolving protein in the inner and outer phases of polymer-stabilized droplets. Cell-sized polymeric microcapsules are assembled by size reduction in the inner core through osmosis followed by evaporation of the middle phase. All methods are developed and validated using the same glass-capillary microfluidic apparatus. This integrative approach not only demonstrates the versatility of our setup, but also holds significant promise for standardizing and customizing the production of polymer-based artificial cells. [ABSTRACT FROM AUTHOR]

Droplet Interface Bilayers (DIBs) constitute a commonly used model of artificial membranes for synthetic biology research applications. However, their practical use is often limited by their requirement to be surrounded by oil. Here we demonstrate in-situ bilayer manipulation of submillimeter, hydrogel-encapsulated droplet interface bilayers (eDIBs). Monolithic, Cyclic Olefin Copolymer/Nylon 3D-printed microfluidic devices facilitated the eDIB formation through high-order emulsification. By exposing the eDIB capsules to varying lysophosphatidylcholine (LPC) concentrations, we investigated the interaction of lysolipids with three-dimensional DIB networks. Micellar LPC concentrations triggered the bursting of encapsulated droplet networks, while at lower concentrations the droplet network endured structural changes, precisely affecting the membrane dimensions. This chemically-mediated manipulation of enclosed, 3D-orchestrated membrane mimics, facilitates the exploration of readily accessible compartmentalized artificial cellular machinery. Collectively, the droplet-based construct can pose as a chemically responsive soft material for studying membrane mechanics, and drug delivery, by controlling the cargo release from artificial cell chassis. Droplet interface bilayers can be used as a model of artificial membranes for synthetic biology and drug delivery applications, however, their accessibility using non-invasive techniques remains challenging. Here, the authors develop an in-situ bilayer manipulation of encapsulated droplet interface bilayers in hydrogel capsules, generated by high-order emulsification in monolithic 3D-printed microfluidic devices. [ABSTRACT FROM AUTHOR]

Developing physical methods to modulate biomolecular clusters and condensates on cell membranes is of great importance for understanding physiological and pathological processes as well as for stimulating novel therapeutic strategies. Here, we propose an effective means to control receptor condensation on the cell membrane via specific adhesion to a supported lipid bilayer (SLB) with nanoscale topography. The specific adhesion is mediated by receptors in the cell membrane that bind their ligands anchored in the SLB. Using Monte Carlo simulations and mean-field theory, we demonstrate that the nanoscale topography of the SLB can enhance condensation of the receptors associated with lipid nanodomains. Our results indicate that SLBs with nanoscale topography proves an effective physical stimulus for tuning condensation of membrane adhesion proteins and lipids in cell membranes, and can serve as a feasible option to control and direct cellular activities, e.g., stem cell differentiation for biomedical and therapeutic applications. Developing physical methods to modulate biomolecular condensates on cell membranes is of great importance for understanding physiological processes and stimulating novel therapeutic strategies. We propose an effective means to control receptor condensation on cell membranes via adhesion to a supported lipid bilayer with nanoscale topography. [ABSTRACT FROM AUTHOR]

Layer Hall effect (LHE), initially discovered in the magnetic topological insulator MnBi2Te4 film, expands the Hall effect family and opens a promising avenue for layertronics applications. In this study, we present an innovative ferroelectric bilayer model to attain a tunable quantum anomalous layer Hall effect (QALHE). This model comprises two ferromagnetic orbital-active Dirac monolayers stacked antiferromagnetically, accompanied by out-of-plane electric polarization. The interplay between the layer-locked Berry curvature monopoles and the intrinsic out-of-plane electric polarization leads to layer-polarized near-quantized anomalous Hall conductance. Using first-principles calculations, we have identified a promising material for this model, namely FeS bilayer. Our calculations demonstrate that the intrinsic out-of-plane electric polarization in the Bernal-stacked FeS bilayer can induce QALHE by regulating the layer-locked Berry curvature of FeS monolayers. Importantly, the intrinsic electric field can be reversed through interlayer sliding. The discovery of ferroelectrically modulated QALHE paves the way for the integrability and non-volatility of layertronics, offering exciting prospects for future applications. [ABSTRACT FROM AUTHOR]

A key player of excitable cells in the heart and brain is the L-type calcium channel CaV1.3. In the heart, it is required for voltage-dependent Ca2+-signaling, i.e., for controlling and modulating atrial cardiomyocyte excitation-contraction coupling. The clustering of CaV1.3 in functionally relevant channel multimers has not been addressed due to a lack of stoichiometric labeling combined with high-resolution imaging. Here, we developed a HaloTag-labeling strategy to visualize and quantify CaV1.3 clusters using STED nanoscopy to address the questions of cluster size and intra-cluster channel density. Channel clusters were identified in the plasma membrane of transfected live HEK293 cells as well as in giant plasma membrane vesicles derived from these cells that were spread on modified glass support to obtain supported plasma membrane bilayers (SPMBs). A small fraction of the channel clusters was colocalized with early and recycling endosomes at the membranes. STED nanoscopy in conjunction with live-cell and SPMB imaging enabled us to quantify CaV1.3 cluster sizes and their molecular density revealing significantly lower channel densities than expected for dense channel packing. CaV1.3 channel cluster size and molecular density were increased in SPMBs after treatment of the cells with the sympathomimetic compound isoprenaline, suggesting a regulated channel cluster condensation mechanism. The authors develop a HaloTag-labeling strategy to quantify the clustering of the L-type calcium channel CaV1.3 using live-cell STED nanoscopy. [ABSTRACT FROM AUTHOR]

Light-induced spin currents with the faster response is essential for the more efficient information transmission and processing. Herein, we systematically explore the effect of light illumination energy and direction on the light-induced spin currents in the W/Y3Fe5O12 heterojunction. Light-induced spin currents can be clearly categorized into two types. One is excited by the low light intensity, which mainly involves the photo-generated spin current from spin photovoltaic effect. The other is caused by the high light intensity, which is the light-thermally induced spin current and mainly excited by spin Seebeck effect. Under low light-intensity illumination, light-thermally induced temperature gradient is very small so that spin Seebeck effect can be neglected. Furthermore, the mechanism on spin photovoltaic effect is fully elucidated, where the photo-generated spin current in Y3Fe5O12 mainly originates from the process of spin precession induced by photons. These findings provide some deep insights into the origin of light-induced spin current. The authors study the light-induced spin current observed in W/Y3Fe5O12 heterojunctions, elucidating the photo-generated spin current, rather than light-thermally induced spin current, by photon-magnon interaction. [ABSTRACT FROM AUTHOR]

We present a strategy for realizing the nonvolatile electrical control of noncollinear magnetism based on first-principles calculations. We confirm that the VAl2S4 monolayer, a rare two-dimensional type-II multiferroic material, shows an in-plane noncollinear 120°-ordered antiferromagnetic ground state and spin spiral order induced out-of-plane ferroelectricity. In VAl2S4 bilayers, we clarify the spin spiral chirality–sliding ferroelectricity locking effect, which enables flexible electrical switching of noncollinear magnetism and corresponding spin spiral chirality through interlayer sliding. Our work provides another perspective for the development of magnetoelectric physics and information storage devices. [ABSTRACT FROM AUTHOR]

To address the spin pumping in the conventional ferromagnetic/"normal" metal systems, we fabricated 6 nm Fe/1–15 nm Rh epitaxial bilayers and determined the g-factor, magnetic anisotropy, and magnetization damping by combining both 0–40 GHz CPW-based frequency-dependent and cavity-based 9.56 GHz in-plane angular-dependent ferromagnetic resonance measurements at room temperature. Auger electron spectroscopy and low-energy electron diffraction show that Rh grows epitaxially on Fe. The epitaxial bilayers exhibit a high spin mixing conductance g mix ↑ ↓ = (2.9 ± 0.2) × 10 19 m−2 and a spin diffusion length in Rhodium λ s d = 9.0 ± 1.3 nm. This makes Rh comparable to Pt and Pd in terms of spin pumping and spin transport efficiency at room temperature. [ABSTRACT FROM AUTHOR]

The best choice today for a realistic method of increasing the energy density of a metal-ion battery is to find novel, effective electrode materials. In this paper, we present a theoretical investigation of the properties of hitherto unreported two-dimensional B 3 C 5 and N 3 C 5 bilayer systems as potential anode materials for lithium-ion batteries. The simulation results show that N 3 C 5 bilayer is not suitable for anode material due to its thermal instability. On the other hand B 3 C 5 is stable, has good electrical conductivity, and is intrinsically metallic before and after lithium intercalation. The low diffusion barrier (0.27 eV) of Li atoms shows a good charge and discharge rate for B 3 C 5 bilayer. Moreover, the high theoretical specific capacity (579.57 mAh/g) connected with moderate volume expansion effect during charge/discharge processes indicates that B 3 C 5 is a promising anode material for Li-ion batteries. [ABSTRACT FROM AUTHOR]

Many plant materials in nature have the ability to change their shape to respond to external stimuli, such as humidity or moisture, to ensure their survival or safe seed release. A well-known example for this phenomenon is the pinecone, which is able to open its scales at low humidity due to the specific bilayer structures of the scale. Inspired by this, we developed a novel humidity-driven actuator based on paper. This was realized by the lamination of untreated paper made from eucalyptus fibers to a paper–carboxymethyl cellulose (CMC) composite. As observed, the hygroexpansion of the composite can be easily controlled by the amount of CMC in the impregnated paper sheet, which, thus, controls the morphologic deformation of the paper bilayer. For a more detailed understanding of these novel paper soft robots, we also studied the dynamic water vapor adsorption, polymer distribution and hygroexpansion of the paper–polymer composites. Finally, we applied a geometrically nonlinear finite element model to predict the bending behavior of paper bilayers and compared the results to experimental data. From this, we conclude that due to the complexity of structure of the paper composite, a universal prediction of the hygromorphic behavior is not a trivial matter. [ABSTRACT FROM AUTHOR]

Transverse thermoelectric generation converts temperature gradient in one direction into an electric field perpendicular to that direction and is expected to be a promising alternative in creating simple‐structured thermoelectric modules that can avoid the challenging problems facing traditional Seebeck‐effect‐based modules. Recently, large transverse thermopower has been observed in closed circuits consisting of magnetic and thermoelectric materials, called the Seebeck‐driven transverse magneto‐thermoelectric generation (STTG). However, the closed‐circuit structure complicates its broad applications. Here, STTG is realized in the simplest way to combine magnetic and thermoelectric materials, namely, by stacking a magnetic layer and a thermoelectric layer together to form a bilayer. The transverse thermopower is predicted to vary with changing layer thicknesses and peaks at a much larger value under an optimal thickness ratio. This behavior is verified in the experiment, through a series of samples prepared by depositing Fe–Ga alloy thin films of various thicknesses onto n‐type Si substrates. The measured transverse thermopower reaches 15.2 ± 0.4 µV K−1, which is a fivefold increase from that of Fe–Ga alloy and much larger than the current room temperature record observed in Weyl semimetal Co2MnGa. The findings highlight the potential of combining magnetic and thermoelectric materials for transverse thermoelectric applications. [ABSTRACT FROM AUTHOR]

Compared to transition metal dichalcogenide (TMD) monolayers, rhombohedral-stacked (R-stacked) TMD bilayers exhibit remarkable electrical performance, enhanced nonlinear optical response, giant piezo-photovoltaic effect and intrinsic interfacial ferroelectricity. However, from a thermodynamics perspective, the formation energies of R-stacked and hexagonal-stacked (H-stacked) TMD bilayers are nearly identical, leading to mixed stacking of both H- and R-stacked bilayers in epitaxial films. Here, we report the remote epitaxy of centimetre-scale single-crystal R-stacked WS2 bilayer films on sapphire substrates. The bilayer growth is realized by a high flux feeding of the tungsten source at high temperature on substrates. The R-stacked configuration is achieved by the symmetry breaking in a-plane sapphire, where the influence of atomic steps passes through the lower TMD layer and controls the R-stacking of the upper layer. The as-grown R-stacked bilayers show up-to-30-fold enhancements in carrier mobility (34 cm2V−1s−1), nearly doubled circular helicity (61%) and interfacial ferroelectricity, in contrast to monolayer films. Our work reveals a growth mechanism to obtain stacking-controlled bilayer TMD single crystals, and promotes large-scale applications of R-stacked TMD. Rhombohedral-stacked (R-stacked) transition metal dichalcogenide bilayers exhibit remarkable properties, but their large-area epitaxial growth remains challenging. Here, the authors report the remote epitaxy of centimetre-scale single-crystal R-stacked WS2 bilayer films on sapphire substrates. [ABSTRACT FROM AUTHOR]

We have observed robust chiral spin torques and non-reciprocal charge transport behaviors in the α-Fe2O3/Pt bilayers through a combination of magnetic field and current-dependent second longitudinal harmonic resistance measurements. The interfacial Dzyaloshinskii–Moriya interaction induced magnetic chirality has been predicted to account for the sign reversal characteristic of the second longitudinal harmonic resistance with increasing the current amplitude. A physical model that considers the chirality dependence of both the asymmetric scattering and the giant Rashba spin–orbit coupling has been set up to uncover the microscopic interactions between charge, spin, and magnetic chirality. Our comprehensive approach leverages the semiclassical Boltzmann theory to validate the consistency between this model and our experimental findings. Through our investigation, we have established the pivotal role of interfacial magnetic chirality in determining both charge and spin transport behaviors within antiferromagnetic insulator/heavy metal bilayer systems. Our work not only enhances the comprehension of spin–orbit torques and non-reciprocal charge transport but also contributes to the broader understanding of these phenomena. The outcomes of this study have broader implications for the advancement of spintronics and related fields. [ABSTRACT FROM AUTHOR]

The alteration of the microstructure and magnetic performance of an exchange bias system, induced by ion irradiation, adversely affects the practical application of spintronic/storage devices in extreme environments. Here, we report systematically the correlation between static and dynamic magnetism and microstructure changes in NiFe/NiO exchange-biased bilayers after high-energy Xe+ ion irradiation. The effect of cascade collision induced by irradiation on exchange bias is studied through Monte Carlo simulations. It is distinguished from the traditional modification caused by keV-level ion irradiation. At low doses, the transition from amorphous to recrystallization occurs in the NiFe layer and the anomalous exchange bias behavior is induced. A step-like structure appears in the magnetic hysteresis loop and the step gradually shifts downward as the dose increases. At high doses, the exchange bias effect is suppressed due to the disordered antiferromagnetic moment caused by heat accumulation during cascade collision, which significantly decreases the thermal stability of the sample by 5–6 times. In addition, the non-monotonic evolution of high-frequency magnetic properties is observed with increasing irradiation doses. This work provides important foundational data for designing future spintronic/memory devices to enhance radiation tolerance and stability. [ABSTRACT FROM AUTHOR]