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The future computing beyond von Neumann era relies heavily on emerging devices that can extensively harness material and device physics to bring novel functionalities and can perform power-efficient and real time computing for artificial intelligence (AI) tasks. Additionally, brain-like computing demands large scale integration of synapses and neurons in practical circuits that requires the nanotechnology to support this hardware development, and all these should come at an affordable process complexity and cost to bring the solutions close to market rather soon. For bringing AI closer to quantum computing and space technologies, additional requirements are operation at cryogenic temperatures and radiation hardening. Considering all these requirements, nanoelectronic devices utilizing ferroic ordering has emerged as one promising alternative. The current review discusses the basic architectures of spintronic and ferroelectric devices for their integration in neuromorphic and analog memory applications, ferromagnetic and ferroelectric domain structures and control of their dynamics for reliable multibit memory operation, synaptic and neuronal leaky-integrate-and-fire (LIF) functions, concluding with their large-scale integration possibilities, challenges and future research directions. [ABSTRACT FROM AUTHOR]

The expanded phthalocyanine (EPc) single‐layer sheets with embedded double transition metals (labeled as TM2EPc) are predicted to be a novel class of highly stable 2D materials with a series of fascinating properties by means of systematic first‐principles calculations, molecular dynamics, and Monte Carlo simulations. Excitingly, the ferromagnetic Cr2EPc and antiferromagnetic Mn2– and Fe2–EPc have high magnetic transition temperatures of 223 (TC), 217 (TN), and 325 K (TN), respectively. This makes them promising candidates for low‐dimensional spintronic applications. Unexpectedly, V2EPc is an antiferromagnetic metal with Dirac cone, while ferromagnetic Cr2EPc exhibits Dirac half‐metallicity. The ultra‐high Fermi velocities near Dirac cones render them promising candidates for applications in high‐speed nanoelectronics and spintronics. Several architectured type‐II heterojunctions show promising power conversion efficiency with maximum 25.19% for Ni2EPc/2H‐WSe2, which has great potential in excitonic solar cell applications. Diverse promising properties endow this class of materials multifunction, which paves the way towards the future applications in nanoelectronics, spintronics, optoelectronics, and photovoltaics. [ABSTRACT FROM AUTHOR]

A van der Waals telluride, NbFeTe2, has been synthesized using chemical vapor transport reactions. The optimized synthetic conditions yield high-quality single crystals with a novel monoclinic crystal structure. Monoclinic NbFeTe2 demonstrates a (100) cleavage plane, bulk ferromagnetism below 87 K, and a metallic ground state—the necessary prerequisites for needed spintronics technologies. [ABSTRACT FROM AUTHOR]

A van der Waals telluride, NbFeTe2, has been synthesized using chemical vapor transport reactions. The optimized synthetic conditions yield high-quality single crystals with a novel monoclinic crystal structure. Monoclinic NbFeTe2 demonstrates a (100) cleavage plane, bulk ferromagnetism below 87 K, and a metallic ground state—the necessary prerequisites for needed spintronics technologies. [ABSTRACT FROM AUTHOR]

The stochastic computing (SC) has been proven to be an energy-efficient way to perform neural network. In this study, we propose a field-free voltage-controlled spintronics SC system based on the magnetic tunnel junction (MTJ). We observe a stochastic switching behavior of the MTJ and that it could be controlled by the voltage applied on the device. The voltage-controlled stochastic switching behavior is used to encode numbers ranging from 0 to 1 into a series of random bit-streams in the SC system. Furthermore, the handwritten recognition task is performed on the MTJ-based SC system, achieving a 95% maximum accuracy, which is comparable with the floating-point based neural network. Our work provides inspiration for the energy-efficient neural network systems. [ABSTRACT FROM AUTHOR]

Magnonics is an emerging field within spintronics that focuses on developing novel magnetic devices capable of manipulating information through the modification of spin waves in nanostructures with submicron size. Here, we provide a confined magnetic rectangular element to modulate the standing spin waves, by changing the saturation magnetisation (MS), exchange constant (A), and the aspect ratio of rectangular magnetic elements via micromagnetic simulation. It is found that the bulk mode and the edge mode of the magnetic element form a hybrid with each other. With the decrease in MS, both the Kittel mode and the standing spin waves undergo a shift towards higher frequencies. On the contrary, as A decreases, the frequencies of standing spin waves become smaller, while the Kittel mode is almost unaffected. Moreover, when the length-to-width aspect ratio of the element is increased, standing spin waves along the width and length become split, leading to the observation of additional modes in the magnetic spectra. For each mode, the vibration style is discussed. These spin dynamic modes were further confirmed via FMR experiments, which agree well with the simulation results. [ABSTRACT FROM AUTHOR]

The ability to electrically manipulate antiferromagnetic magnons, essential for extending the operating speed of spintronic devices into the terahertz regime, remains a major challenge. This is because antiferromagnetic magnetism is challenging to perturb using traditional methods such as magnetic fields. Recent developments in spin-orbit torques have opened a possibility of accessing antiferromagnetic magnetic order parameters and controlling terahertz magnons, which has not been experimentally realised yet. Here, we demonstrate the electrical manipulation of sub-terahertz magnons in the α-Fe2O3/Pt antiferromagnetic heterostructure. By applying the spin-orbit torques in the heterostructure, we can modify the magnon dispersion and decrease the magnon frequency in α-Fe2O3, as detected by time-resolved magneto-optical techniques. We have found that optimal tuning occurs when the Néel vector is perpendicular to the injected spin polarisation. Our results represent a significant step towards the development of electrically tunable terahertz spintronic devices. Antiferromagnetic spintronics offer high speed operations, and reduced issues with stray fields compared to ferromagnetic systems, however, antiferromagnets are typically more challenging to manipulate electrically. Here, Yang, Kim, and coauthors demonstrate electrical control of magnon dispersion and frequency in an α-Fe2O3/Pt heterostructure. [ABSTRACT FROM AUTHOR]

Superconducting junctions with a ferromagnet as the weak link, where triplet correlations can transport supercurrents over a substantial distance, have been of long-standing interest. In this work, we study the triplet transport in planar La0.7Sr0.3MnO3 (LSMO) nanowire Josephson junctions with NbTi superconducting contacts. By meticulous ion etching with an artificial Pt hard mask, the NbTi/LSMO bilayer is structured to form an LSMO bridge without damaging its top layer. We observe superconducting (critical) currents of the order of 109 A/m2 in a junction with a length of 1.3 μm, and distinguishing superconducting quantum interference (SQI) patterns when sweeping a magnetic field perpendicular ( B ⊥ ) to the plane of the wire or parallel ( B ∥ ) to the plane and along the wire. The observed Gaussian-shaped SQI pattern is attributed to the diffusive transport of triplet pairs in the LSMO. Our work demonstrates that combinations of oxide magnets with conventional (s-wave) alloy superconductors can be a promising new route to realizing superconducting spintronics. [ABSTRACT FROM AUTHOR]

The spin pumping in YIG/Pt structures by surface and backward volume magnetostatic waves has been studied experimentally. It has been shown that the efficiency of the generation of the spin current increases at frequencies of spin waves corresponding to van Hove singularities in the density of states. The results of this work are important for the development of magnon spintronics devices. [ABSTRACT FROM AUTHOR]

A general expression for the magnetostatic field generated by mechanical deformations to a ferromagnetic material in the continuum description is derived. Linearization with respect to the displacement vector is shown to be well defined. To demonstrate the use of the formulation, two examples are discussed. First, a complete derivation of the magneto‐rotation coupling for a uniformly magnetized film is given. Second, the lowest asymmetric mode of Lamb waves propagating through a magnetic vortex is shown to induce an in‐plane magnetostatic field localized around the vortex core. [ABSTRACT FROM AUTHOR]

Herein, we investigate the effect of tilt mismatch on the quantum oscillations of spin transport properties in two-dimensional asymmetrically tilted Dirac cone systems. This study involves the examination of conductance oscillation in two distinct junction types: transverse- and longitudinal-tilted Dirac cones (TTDCs and LTDCs). Our findings reveal an unusual quantum oscillation of spin-polarized conductance within the TTDC system, characterized by two distinct anomaly patterns within a single period, labeled as the linear conductance phase and the oscillatory conductance phase. Interestingly, these phases emerge in association with tilt-induced orbital pseudo-magnetization and exchange interaction. Our study also demonstrates that the structure of the LTDC can modify the frequency of spin conductance oscillation, and the asymmetric effect within this structure results in a quantum beating pattern in oscillatory spin conductance. We note that an enhancement in the asymmetric longitudinal tilt velocity ratio within the structure correspondingly amplifies the beating frequency. Our research potentially contributes valuable insights for detecting the asymmetry of tilted Dirac fermions in type-I Dirac semimetal-based spintronics and quantum devices. [ABSTRACT FROM AUTHOR]

The topological skyrmions in ferrimagnet systems provide new opportunities to investigate the fundamental spin dynamics. Effective manipulation of ferrimagnet skyrmion motion is a vital task for future spintronics applications, motivating intense research on magnetization dynamics with voltage as driving sources. In this work, the skyrmion in ferrimagnets driven by voltage controlled magnetic anisotropy gradients, which tends to move toward the low anisotropy area and has a constant velocity, is investigated. Thiele's theory analysis is reported on the velocities of the skyrmion dependencies on the anisotropy gradient, the net angular momentum density, and the damping coefficient, which are confirmed nicely by the atomistic simulations. It is demonstrated that the velocity of the skyrmion reaches to a maximum value at a nonzero net angular momentum density δs different from the domain wall, and the Hall angle of ferrimagnet skyrmions can be controlled by δs. The results are useful for the understanding of ferrimagnet skyrmion dynamics and may open an alternative way for the design of ferrimagnet spintronic devices. [ABSTRACT FROM AUTHOR]

To comprehend the mechanical, electronic, and magnetic properties of chalcogenides HgSm2S/Se4, a DFT-oriented thorough investigation is carried out. The elastic constants and spin-dependent electrical characteristics are determined by using the PBEsol-GGA functional and (mBJ) potential correspondingly. Through optimization, a sufficient amount of energy is discharged by the FM state as compared to nonmagnetic states. By investigating Born stability criteria and formation energy, the structural stabilities of both spinels are verified. The calculated Poisson's and Pugh's ratios showed that both spinels are ductile. The estimation of Curie temperature has supported the existence of a ferromagnetic nature at room temperature. Moreover, the presence of ferromagnetism in both spinels is confirmed by spin-oriented electrical characteristics, owing to the coupling between component states associated with Sm and S/Se. [ABSTRACT FROM AUTHOR]

The solid thin films of Py/Pt and Py/W heterostructures have been studied using the ferromagnetic resonance method. The temperature dependences of the Gilbert damping parameter and voltage of the inverse spin Hall effect (ISHE) have been obtained in the 5–290 K temperature range. An abnormal increase in the Gilbert damping parameter in the vicinity of 50 K and a change in the voltage of ISHE has been found. It has been concluded that an increase in the Gilbert damping parameter is of spin-orbital nature. [ABSTRACT FROM AUTHOR]

Magnetization switching in ferromagnets has so far been limited to the current-induced spin–orbit–torque effects. Recent observation of helicity-independent all-optical magnetization switching (HI-AOS) in an exchange-coupled ferromagnet–ferrimagnet (FM-FEM) heterostructures expanded the range and applicability of such ultrafast heat-driven magnetization switching. Here we report the element-resolved HI-AOS dynamics of such an exchange-coupled system, using a modified microscopic three-temperature model. We have studied the effect of (i) the Curie temperature of the FM, (ii) FEM composition, (iii) the long-range Ruderman–Kittel–Kasuya–Yosida (RKKY) exchange-coupling strength, and (iv) the absorbed optical energy on the element-specific time-resolved magnetization dynamics. The phase-space of magnetization illustrates how the RKKY coupling strength and the absorbed optical energy influence the switching time. Our analysis demonstrates that the threshold switching energy depends on the composition of the FEM and the switching time depends on the Curie temperature of the FM as well as RKKY coupling strength. This simulation anticipates new insights into developing faster and more energy-efficient spintronics devices.

Today’s semiconductor devices use the charges of electrons and holes for tasks like light emission and signal processing. Semiconductor spintronics, a newer field, aims to exploit the spin of charge carriers to advance technologies like magnetic lasers, sensors, and transistors. Spintronics could enable the creation of memory, sensing, and logic devices with capabilities that charge-based devices can't match. This work explores the progress made with spintronic materials and devices, their current uses, and what the future might hold. A key feature of emerging spintronic logic devices is their ability to generate highly spin-polarized currents in two- and three-terminal tunnel junctions, which can lead to devices that consume much less power than traditional charge-based ones. Recent advancements in material engineering give hope for the rapid development and deployment of these new spintronic technologies.

Abstract Quantum technologic and spintronic applications require reliable material platforms that enable significant and long‐living spin polarization of excitations, the ability to manipulate it optically in external fields, and the possibility to implement quantum correlations between spins, i.e., entanglement. Here it is demonstrated that these conditions are met in bulk crystals of lead halide perovskites. A giant optical orientation of 85% of excitons, approaching the ultimate limit of unity, in FA0.9Cs0.1PbI2.8Br0.2 crystals is reported. The exciton spin orientation is maintained during the exciton lifetime of 55 ps resulting in high circular polarization of the exciton emission. The optical orientation is robust to detuning of the excitation energy up to 0.3 eV above the exciton resonance and remains larger than 20% up to detunings of 0.9 eV. It evidences pure chiral selection rules and suppressed spin relaxation of electrons and holes, even with large kinetic energies. The exciton and electron–hole recombinations are distinguished by means of the spin dynamics detected via coherent spin quantum beats in magnetic field. Further, electron–hole spin correlations are demonstrated through linear polarization beats after circularly polarized excitation. These findings are supported by atomistic calculations. All‐in‐all, the results establish lead halide perovskite semiconductors as suitable platform for quantum technologies.

chemical attributes. The specific domain within technology referred to as spintronics, encompasses the realm of spin transport electronics. Spintronics delves into the electron spin, its inherent magnetic moment and fundamental charge, and the manipulation of these intrinsic characteristics to develop solid-state devices. In metallic systems, spintronics encloses phenomena like spin-charge coupling, which includes ferro- and ferrimagnetic materials, giant and colossal magnetoresistive materials, and metallic spins. Among the most versatile materials in the evidence of exotic properties, one of the most representative families is the so-called perovskites, widely studied in recent years including their properties in solar cell technology. Here, we present some crystallographic, compositional, morphological, optical, and magnetic attributes of the Ca2TiFeO6 double perovskite material, synthesized by the standard solid-state reaction method from high-purity precursor oxides. Rietveld refinement of experimental X-ray diffraction data revealed that this material crystallizes in a monoclinic perovskite-type structure with alternating ordering of Ti-Fe cations along the three crystallographic axes. The strongly granular surface character of the Ca2TiFeO6 materials was observed in the images from a scanning electron microscope; the electron X-ray energy dispersive spectra revealed a close match of sample composition to that expected from their chemical formula. The diffuse reflectance spectrum showed the semiconductor feature of the material with a 1.02 eV bandgap. The magnetic characterization in the 50 K < T < 335 K regime and the applied fields up to 1 kOe showed the ferromagnetic response of the material over the entire temperature range measured. These properties are promising in the spintronics industry for devices where the same material serves to process, record, read, and erase information as in the spin transistors.

Abstract Spin‐transfer torque (STT) and spin‐orbit torque (SOT) form the core of spintronics, allowing for the control of magnetization through electric currents. While the sign of SOT can be manipulated through material and structural engineering, it is conventionally understood that STT lacks a degree of freedom in its sign. However, this study presents the first demonstration of manipulating the STT sign by engineering heavy metals adjacent to magnetic materials in magnetic heterostructures. Spin torques are quantified through magnetic domain‐wall speed measurements, and subsequently, both STT and SOT are systematically extracted from these measurements. The results unequivocally show that the sign of STT can be either positive or negative, depending on the materials adjacent to the magnetic layers. Specifically, Pd/Co/Pd films exhibit positive STT, while Pt/Co/Pt films manifest negative STT. First‐principle calculations further confirm that the sign reversal of STT originates from the sign reversal of spin polarization of conduction electrons.

An exchange bias (EB) model taking the setting process into account is developed to study the effect of the crucial parameters, such as the AFM anisotropy constant (K A F ), the setting temperature ( T s e t ), and the physical microstructure on the exchange bias field of an AFM/FM system. The magnetization dynamics of the EB system is treated using the kinetic Monte Carlo approach and by integrating the Landau–Lifshitz–Gilbert equation for AFM and FM layers, respectively. We first investigate the variation of the exchange bias field (H E B ) as a function of K A F in the IrMn/CoFe system. It is found that H E B strongly depends on the energy barrier dispersion determined by dispersions of K A F and the grain volume. It is shown that the H E B is affected by the physical microstructure of the IrMn layer: film thickness and grain diameter. We also demonstrate that the maximum setting fraction (f s e t ) related to H E B can be achieved by optimizing the value of K A F and T s e t . The simulation results of the setting process are in good agreement with previous experimental works. This confirms the validity of the EB model, including the setting process that can be used as a powerful tool for the application of spintronics, especially for read sensor design to achieve high thermal stability with scaling down of components. [ABSTRACT FROM AUTHOR]

In this Perspective article, we briefly present the current state and discuss some future perspectives on hybrid molecular spintronics and smart molecular spintronics materials. We discuss the role of the chirality induced spin selectivity effect, where molecular chirality can be employed to manipulate spin states, potentially also including quantum coherent spin qubit states. We comment on some of the challenges and suggest future potential of magnetic biomolecules and chemical modification of 2D materials for these purposes. [ABSTRACT FROM AUTHOR]

Electric field control of the exchange bias effect across ferromagnet/antiferromagnet (FM/AF) interfaces has offered exciting potentials for low-energy-dissipation spintronics. In particular, the solid-state magneto-ionic means is highly appealing as it may allow reconfigurable electronics by transforming the all-important FM/AF interfaces through ionic migration. In this work, we demonstrate an approach that combines the chemically induced magneto-ionic effect with the electric field driving of nitrogen in the Ta/Co0.7Fe0.3/MnN/Ta structure to electrically manipulate exchange bias. Upon field-cooling the heterostructure, ionic diffusion of nitrogen from MnN into the Ta layers occurs. A significant exchange bias of 618 Oe at 300 K and 1484 Oe at 10 K is observed, which can be further enhanced after a voltage conditioning by 5 and 19%, respectively. This enhancement can be reversed by voltage conditioning with an opposite polarity. Nitrogen migration within the MnN layer and into the Ta capping layer cause the enhancement in exchange bias, which is observed in polarized neutron reflectometry studies. These results demonstrate an effective nitrogen-ion based magneto-ionic manipulation of exchange bias in solid-state devices.

Abstract Phosphorene is a unique semiconducting two-dimensional platform for enabling spintronic devices integrated with phosphorene nanoelectronics. Here, we have designed an all phosphorene lattice lateral spin valve device, conceived via patterned magnetic substituted atoms of 3d-block elements at both ends of a phosphorene nanoribbon acting as ferromagnetic electrodes in the spin valve. Through First-principles based calculations, we have extensively studied the spin-dependent transport characteristics of the new spin valve structures. Systematic exploration of the magnetoresistance (MR) of the spin valve for various substitutional atoms and bias voltage resulted in a phase diagram offering a colossal MR for V and Cr-substitutional atoms. Such MR can be directly attributed to their specific electronic structure, which can be further tuned by a gate voltage, for electric field controlled spin valves. The spin-dependent transport characteristics here reveal new features such as negative conductance oscillation and switching of the sign of MR due to change in the majority spin carrier type. Our study creates possibilities for the design of nanometric spin valves, which could enable integration of memory and logic elements for all phosphorene 2D processors.

The present investigation reports the swift heavy ion induced effects on cerium oxide (CeO2) thin films. These thin films were deposited on Si (111) substrates by the electron-beam evaporation method and irradiated by a 100 MeV O7+ ion beam with different ion fluences. X-ray diffraction analysis of these films confirms the stable fluorite phase of CeO2 even after the higher fluence of irradiations. Raman measurement also supports the presence of the F2g phase of CeO2 and the presence of defect states. The Gaussian deconvolution of photoluminescence (PL) spectra reveals various defect-associated peaks. The broad peaks in the PL spectra are associated with oxygen vacancies and are red-shifted (494–520 nm) with ion fluences. The surface morphological images show the modification in the surface roughness with ion irradiation and the re-growth of smaller circular-formed nanoparticles on the surface is observed at the fluence of 5 × 1011 ions/cm2. Magnetic measurements show an enhancement in magnetic ordering with ion irradiation. All the samples demonstrate room temperature ferromagnetism with magnetic saturation (Ms) up to 14.57 emu/cm3. The saturation magnetization in irradiated thin films is directly correlated to the area under the peak of defect-associated PL emission. The mechanism such as the oxygen vacancy-based F-center exchange model is considered to understand the enhancement of ferromagnetism in ion irradiated CeO2 thin films. Some popular theoretical models are also employed to determine various magnetic parameters. [ABSTRACT FROM AUTHOR]

In this work, we show that a magnon spin capacitor can be realized at a junction between two exchange coupled ferromagnets. In this junction, the buildup of magnon spin over the junction is coupled to the difference in magnon chemical potential, realizing the magnon spin analogue of an electrical capacitor. The relation between magnon spin and magnon chemical potential difference directly follows from considering the magnon density–density interaction between the two ferromagnets. We analyze the junction in detail by considering spin injection and detection from normal metal leads, the tunneling current across the junction, and magnon decay within the ferromagnet, showing that such a structure realizes a magnon spin capacitor in series with a spin resistor. Choosing yttrium iron garnet as the ferromagnet, we numerically calculate the magnon spin capacitance which ranges from picofarad to microfarad, depending on the area of the junction. We therefore conclude that the magnon spin capacitor could directly be of use in applications. [ABSTRACT FROM AUTHOR]

In this study, we investigate the pseudo-static magnetic properties of Permalloy conical frustum nanowires using micromagnetic simulations. We thoroughly examine how both the major and minor radii influence the magnetic reversal mechanism when an external magnetic field is applied parallel to the nanowire axis. The obtained results show that under specific geometrical conditions, magnetization reverts though a Bloch point-type domain wall. In these cases, hysteresis curves exhibit two Barkhausen jumps during magnetization reversal, forming a plateau field range in which a Bloch point domain wall nucleates and propagates until its annihilation after the second Barkhausen jump. The nucleation of a Bloch point domain wall in a frustum conical nanowire geometry is reported. These findings highlight the significance of this geometry in nucleating these attractive topological defects for promising applications. [ABSTRACT FROM AUTHOR]

Phosphorene is a unique semiconducting two-dimensional platform for enabling spintronic devices integrated with phosphorene nanoelectronics. Here, we have designed an all phosphorene lattice lateral spin valve device, conceived via patterned magnetic substituted atoms of 3d-block elements at both ends of a phosphorene nanoribbon acting as ferromagnetic electrodes in the spin valve. Through First-principles based calculations, we have extensively studied the spin-dependent transport characteristics of the new spin valve structures. Systematic exploration of the magnetoresistance (MR) of the spin valve for various substitutional atoms and bias voltage resulted in a phase diagram offering a colossal MR for V and Cr-substitutional atoms. Such MR can be directly attributed to their specific electronic structure, which can be further tuned by a gate voltage, for electric field controlled spin valves. The spin-dependent transport characteristics here reveal new features such as negative conductance oscillation and switching of the sign of MR due to change in the majority spin carrier type. Our study creates possibilities for the design of nanometric spin valves, which could enable integration of memory and logic elements for all phosphorene 2D processors. [ABSTRACT FROM AUTHOR]

Topological spin textures are characterized by magnetic topological charges, Q, which govern their electromagnetic properties. Recent studies have achieved skyrmion bundles with arbitrary integer values of Q, opening possibilities for exploring topological spintronics based on Q. However, the realization of stable skyrmion bundles in chiral magnets at room temperature and zero magnetic field — the prerequisite for realistic device applications — has remained elusive. Here, through the combination of pulsed currents and reversed magnetic fields, we experimentally achieve skyrmion bundles with different integer Q values — reaching a maximum of 24 at above room temperature and zero magnetic field — in the chiral magnet Co8Zn10Mn2. We demonstrate the field-driven annihilation of high-Q bundles and present a phase diagram as a function of temperature and field. Our experimental findings are consistently corroborated by micromagnetic simulations, which reveal the nature of the skyrmion bundle as that of skyrmion tubes encircled by a fractional Hopfion. Manipulation of topological charge at room temperature is a key tenet of skyrmionics. Here, the authors demonstrate tunable topological charges in skyrmion bundles at room temperature and zero magnetic field. [ABSTRACT FROM AUTHOR]

Lead halide perovskites (LHPs) containing organic parts are emerging optoelectronic materials with a wide range of applications thanks to their high optical absorption, carrier mobility, and easy preparation methods. They possess spin-dependent properties, such as strong spin–orbit coupling (SOC), and are promising for spintronics. The Rashba effect in LHPs can be manipulated by a magnetic field and a polarized light field. Considering the surfaces and interfaces of LHPs, light polarization-dependent optoelectronics of LHPs has attracted attention, especially in terms of spin-dependent photocurrents (SDPs). Currently, there are intense efforts being made in the identification and separation of SDPs and spin-to-charge interconversion in LHP. Here, we provide a comprehensive review of second-order nonlinear photocurrents in LHP in regard to spintronics. First, a detailed background on Rashba SOC and its related effects (including the inverse Rashba–Edelstein effect) is given. Subsequently, nonlinear photo-induced effects leading to SDPs are presented. Then, SDPs due to the photo-induced inverse spin Hall effect and the circular photogalvanic effect, together with photocurrent due to the photon drag effect, are compared. This is followed by the main focus of nonlinear photocurrents in LHPs containing organic parts, starting from fundamentals related to spin-dependent optoelectronics. Finally, we conclude with a brief summary and future prospects. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) ferromagnets have attracted significant interest for their potential in spintronic device miniaturization, especially since the discovery of ferromagnetic ordering in monolayer materials such as CrI3 and Fe3GeTe2 in 2017. This study presents a detailed investigation into the effects of the Hubbard U parameter, biaxial strain, and structural distortions on the magnetic characteristics of T″-phase VTe2. We demonstrate that setting the Hubbard U to 0 eV provides an accurate representation of the observed structural, magnetic, and electronic features for both bulk and monolayer T″-phase VTe2. The application of strain reveals two distinct ferromagnetic states in the monolayer T″-phase VTe2, each characterized by minor structural differences, but notably different magnetic moments. The T″-1 state, with reduced magnetic moments, emerges under compressive strain, while the T″-2 state, featuring increased magnetic moments, develops under tensile strain. Our analysis also compares the magnetic anisotropy between the T and T″ phases of VTe2, highlighting that the periodic lattice distortion in the T″-phase induces an in-plane anisotropy, which makes it a material with an easy-axis of magnetization. Monte Carlo simulations corroborate our findings, indicating a high Curie temperature of approximately 191 K for the T″-phase VTe2. Our research not only sheds light on the critical aspects of the VTe2 system but also suggests new pathways for enhancing low-dimensional magnetism, contributing to the advancement of spintronics and straintronics. [ABSTRACT FROM AUTHOR]

The molecular orientation of liquid crystalline (LC) hydrogels has the potential to induce a range of functionalities that can deliver great mechanical strength. Sacran is a supergiant LC polysaccharide isolated from the cyanobacterium Aphanothece sacrum with a high amount of anionic functional groups such as sulfates and carboxylates. In this article, ultra-strong sacran hydrogels and their dried fibers were produced by cross-linking under injection flow with trivalent metal ions such as Al3+, Cr3+, Fe3+, In3+, and rare-earth metal ions such Er3+ and Sr3+. Crossed-polarizing microscopy and X-ray diffraction imaging revealed a uniaxial molecular orientation in the LC gel fiber, resulting in outstanding mechanical characteristics. [ABSTRACT FROM AUTHOR]

A sample with the spin Hall effect causes spin-orbit coupling to induce spin-polarized electrons that accumulate inverse signals on either side of the sample. In this study, a multiterminal device was fabricated using a tantalum Hall bar and a spin injector of the permalloy nanowire to detect inverse Hall effect signals. This device can read the different spin Hall signals emitted from the magnetic state of the permalloy wire. Our results reveal that the different magnetic states of the permalloy wire cause an asymmetric shift of the inverse spin Hall voltage and also display various signals at opposite directions of currents. As the input current increases, the voltage also exhibits nonlinear growth. This indicates that the inverse spin Hall signals are affected by the magnetic state of the permalloy wire and the input current direction. This also indicates that the inverse spin Hall signals from the multiterminal device can inspire the design of the sensor for detecting spin electrons and neuron-like magnetization states. [ABSTRACT FROM AUTHOR]

The Nernst effect describes a linear relationship between orthogonal components of a magnetic field, a temperature gradient, and a resulting transverse electric field. A non-local electrical measurement, where injection and detection are physically separated on the specimen, serves as a versatile and effective platform for measuring spin and thermal effects due to the avoided interference with a charge current directly. Here, we quantify the Nernst coefficient of Pt, a common material for spin injection in non-local geometries, by a non-local electrical measurement under modulated temperature and magnetic field and finite element analysis for modeling heat transfer. We determine the Nernst coefficient of Pt from room temperature (8.56 nV K − 1 T − 1 ) to 10 K (29.3 nV K − 1 T − 1 ). Beyond the quantification of the Nernst coefficient, our results show that careful consideration of the thermal properties of the thermal sink and electrode materials is needed when making an interpretation of non-local electrical measurements. [ABSTRACT FROM AUTHOR]

In this work, we have observed that some chiral boron clusters ( B 16 − , B 20 − , B 24 − , and B 28 − ) can simultaneously have helical molecular orbitals and helical spin densities; these seem to be the first compounds discovered to have this intriguing property. We show that chiral Jahn–Teller distortion of quasi-planar boron clusters drives the formation of the helical molecular spin densities in these clusters and show that elongation/enhancement in helical molecular orbitals can be achieved by simply adding more building blocks via a linker. Aromaticity of these boron clusters is discussed. Chiral boron clusters may find potential applications in spintronics, such as molecular magnets. [ABSTRACT FROM AUTHOR]