可弯曲与拉伸Bi2Te3/铁磁异质结的轨道霍尔效应

… ferromagnets with different H C s. (34) In our system, the sample contains only a single ferromagnetic … by the coupling between the p-orbital of Bi and the d-orbital of Cr. (19) This picture …

… –orbit coupling (SOC) causes electrons with different spins to deflect in different directions and produce a spin current transverse to the applied charge current (spin Hall effect … of Bi2Te3 …

The half-quantized Hall phase represents a unique metallic or semi-metallic state of matter characterized by a fractional quantum Hall conductance, precisely half of an integer ν multiple of e2/h. Here we demonstrate the existence of a Z/2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathbb{Z}}/2$$\end{document} topological invariant that sets the half-quantized Hall phase apart from two-dimensional ordinary metallic ferromagnets. The Z/2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathbb{Z}}/2$$\end{document} classification is determined by the line integral of the intrinsic anomalous Hall conductance, which is safeguarded by two distinct categories of local unitary and anti-unitary symmetries in proximity to the Fermi surface of electron states. We further validate the Z/2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathbb{Z}}/2$$\end{document} topological order in the context of the quantized Hall phase by examining semi-magnetic topological insulator Bi2Te3 and Bi2Se3 film for ν = 1 and topological crystalline insulator SnTe films for ν = 2 or 4. Our findings pave the way for future exploration and understanding of topological metals and their unique properties. Topological quantization is a cornerstone of modern condensed matter physics, as epitomized by the well-known integer or even/odd quantization in topological insulators. In this work, Fu and other authors provided a rigorous characterization of the half-integer quantized invariant of metallic ferromagnets.

In recent years, the study of two-dimensional (2D) intrinsic antiferromagnetic (AFM) topological insulators (TIs) has attracted considerable attention due to their unique electronic and magnetic properties, which are promising for the advancement of quantum computing and spintronic applications. MnBi2Te4, recognized as the first intrinsic AFM TI, provides a unique platform for examining theoretical predictions in the field of quantum materials. This discovery has sparked extensive research and led to numerous new insights that have improved the understanding of the interplay between magnetism and topology in two-dimensional systems. The homologous series (MnBi2Te4)(Bi2Te3)n, with its alternating layers of MnBi2Te4 and Bi2Te3, exhibits tunable magnetic and topological properties, making it a subject of intense investigation. This review comprehensively examines advances in the (MnBi2Te4)(Bi2Te3)n homologous series, including their synthesis, structural characterization, and study of magnetic and electronic properties. Key experimental observations are highlighted, which have been instrumental in elucidating the fundamental physics of these materials. Additionally, several unresolved questions and potential future research directions are discussed, providing valuable insights for researchers seeking to advance this integrated field. This review serves as a reference for understanding the potential and future advancements of 2D AFM TIs, fostering further exploration of their complex and promising properties.

The importance of global band topology is unequivocally recognized in condensed matter physics, and new states of matter, such as topological insulators, have been discovered. Owing to their bulk band topology, 3D topological insulators possess a massless Dirac dispersion with spin–momentum locking at the surface. Although 3D topological insulators were originally proposed in time-reversal invariant systems, the onset of a spontaneous magnetization or, equivalently, a broken time-reversal symmetry leads to the formation of an exchange gap in the Dirac band dispersion. In such magnetic topological insulators, tuning of the Fermi level in the exchange gap results in the emergence of a quantum Hall effect at zero magnetic field, that is, of a quantum anomalous Hall effect. Here, we review the basic concepts of magnetic topological insulators and their experimental realization, together with the discovery and verification of their emergent properties. In particular, we discuss how the development of tailored materials through heterostructure engineering has made it possible to access the quantum anomalous Hall effect, the topological magnetoelectric effect, the physics related to the chiral edge states that appear in these materials and various spintronic phenomena. Further theoretical and experimental research on magnetic topological insulators will provide fertile ground for the development of new concepts for next-generation electronic devices for applications such as spintronics with low energy consumption, dissipationless topological electronics and topological quantum computation. Magnetic topological insulators enable the investigation of the interplay between magnetism and topological electronic states. This Review summarizes the basic notions of magnetic topological insulators and the progress in the experimental realization of exotic topological phenomena. The chemical doping of topological insulators with transition metal elements induces a spontaneous magnetization that interacts with the topological surface state to open a mass gap at the Dirac point. The precise tuning of the Fermi level at the mass gap enables the observation of the quantum anomalous Hall effect — a zero-magnetic-field quantum Hall effect arising in the presence of a spontaneous magnetization — which is further stabilized by heterostructure engineering. Chiral edge conduction associated with the quantum anomalous Hall effect is manipulated by magnetic domain walls, and the edge modes can be turned into chiral Majorana edge modes via proximity coupling with a superconductor. Heterostructure engineering and terahertz measurements enable the observation of the quantized topological magnetoelectric effect. The spin–momentum-locked conduction electrons in the surface state lead to versatile spintronic functionalities, such as an efficient generation of spin transfer torque, as a result of charge-to-spin conversion. The further development of materials design and engineering will realize the quantum anomalous Hall effect at higher temperatures, the control of this state with external fields and exotic topological states of matter. The chemical doping of topological insulators with transition metal elements induces a spontaneous magnetization that interacts with the topological surface state to open a mass gap at the Dirac point. The precise tuning of the Fermi level at the mass gap enables the observation of the quantum anomalous Hall effect — a zero-magnetic-field quantum Hall effect arising in the presence of a spontaneous magnetization — which is further stabilized by heterostructure engineering. Chiral edge conduction associated with the quantum anomalous Hall effect is manipulated by magnetic domain walls, and the edge modes can be turned into chiral Majorana edge modes via proximity coupling with a superconductor. Heterostructure engineering and terahertz measurements enable the observation of the quantized topological magnetoelectric effect. The spin–momentum-locked conduction electrons in the surface state lead to versatile spintronic functionalities, such as an efficient generation of spin transfer torque, as a result of charge-to-spin conversion. The further development of materials design and engineering will realize the quantum anomalous Hall effect at higher temperatures, the control of this state with external fields and exotic topological states of matter.

Two-dimensional (2D) ferromagnetic materials with unique magnetic properties have great potential for next-generation spintronic devices with high flexibility, easy controllability, and high heretointegrability. However, realizing magnetic switching with low power consumption at room temperature is challenging. Here, we demonstrate the room-temperature spin-orbit torque (SOT) driven magnetization switching in an all-van der Waals (vdW) heterostructure using an optimized epitaxial growth approach. The topological insulator Bi2Te3 not only raises the Curie temperature of Fe3GeTe2 (FGT) through interfacial exchange coupling but also works as a spin current source allowing the FGT to switch at a low current density of ~2.2×106 A/cm2. The SOT efficiency is ~2.69, measured at room temperature. The temperature and thickness-dependent SOT efficiency prove that the larger SOT in our system mainly originates from the nontrivial topological origin of the heterostructure. Our experiments enable an all-vdW SOT structure and provides a solid foundation for the implementation of room-temperature all-vdW spintronic devices in the future.

… spin-orbit coupling, a transverse response can occur even without an external magnetic field, leading to the spin Hall effect[14–… In MBT/Bi2Te3 heterostructures, the Bi2Te3 layers, which …

Magnetic topological quantum materials (TQMs) provide a fertile ground for the emergence of fascinating topological magneto-electric effects. Recently, the discovery of intrinsic antiferromagnetic (AFM) topological insulator MnBi2Te4 that could realize quantized anomalous Hall effect and axion insulator phase ignited intensive study on this family of TQM compounds. Here, we investigated the AFM compound MnBi4Te7 where Bi2Te3 and MnBi2Te4 layers alternate to form a superlattice. Using spatial- and angle-resolved photoemission spectroscopy, we identified ubiquitous (albeit termination dependent) topological electronic structures from both Bi2Te3 and MnBi2Te4 terminations. Unexpectedly, while the bulk bands show strong temperature dependence correlated with the AFM transition, the topological surface states with a diminishing gap show negligible temperature dependence across the AFM transition. Together with the results of its sister compound MnBi2Te4, we illustrate important aspects of electronic structures and the effect of magnetic ordering in this family of magnetic TQMs.

… the normal Hall effect is shown in Fig. 8(a)–(d). In Fig. … –orbit coupling (SOC) and the T C in FGT/BT heterostructures, … than from SOC-induced magnetic anisotropy energy Our work …

The Orbital Hall effect, which originates from materials with weak spin-orbit coupling, has attracted considerable interest for spin-orbitronic applications. Here, we demonstrate the inverse effect of the orbital Hall effect and observe orbitronic terahertz emission in the Ti and Mn materials. Through spin-orbit transition in the ferromagnetic layer, the generated orbital current can be converted to charge current in the Ti and Mn layers via the inverse orbital Hall effect. Furthermore, the inserted W layer provides an additional conversion of the orbital-charge current in the Ti and Mn layers, significantly enhancing the orbitronic terahertz emission. Moreover, the orbitronic terahertz emission can be manipulated by cooperating with the inverse orbital Hall effect and the inverse spin Hall effect in the different sample configurations. Our results not only discover the physical mechanism of condensed matter physics but also pave the way for designing promising spin-orbitronic devices and terahertz emitters.

… spectroscopy and inverse spin-Hall effect (ISHE) measurements over … The growth rate of the Bi2Te3 and MnBi2Te4 films were … -based heterostructures in lowtemperature spin-orbit and …

Bi2Te3‐based materials are not only the most important and widely used room temperature thermoelectric (TE) materials but are also canonical examples of topological insulators in which the topological surface states are protected by the time‐reversal symmetry. High‐performance thin films based on Bi2Te3 have attracted worldwide attention during the past two decades due primarily to their outstanding TE performance as highly efficient TE coolers and as miniature and flexible TE power generators for a variety of electronic devices. Moreover, intriguing topological phenomena, such as the quantum anomalous Hall effect and topological superconductivity discovered in Bi2Te3‐based thin films and heterostructures, have shaped research directions in the field of condensed matter physics. In Bi2Te3‐based films and heterostructures, delicate control of the carrier transport, film composition, and microstructure are prerequisites for successful device operations as well as for experimental verification of exotic topological phenomena. This review summarizes the recent progress made in atomic defect engineering, carrier tuning, and band engineering down to a nanoscale regime and how it relates to the growth and fabrication of high‐quality Bi2Te3‐based films. The review also briefly discusses the physical insight into the exciting field of topological phenomena that were so dramatically realized in Bi2Te3‐ and Bi2Se3‐based structures. It is expected that Bi2Te3‐based thin films and heterostructures will play an ever more prominent role as flexible TE devices collecting and converting low‐level (body) heat into electricity for numerous electronic applications. It is also likely that such films will continue to be a remarkable platform for the realization of novel topological phenomena.

On the basis of an experimental and first-principles study, strain effects on the thermoelectric properties of bismuth telluride (Bi2Te3) thin films were investigated. Bi2Te3 thin films were deposited on flexible polyimide substrates using a radio frequency magnetron sputtering method at a substrate temperature of 200 °C. Prior to deposition, various compressive and tensile bending strains were applied to the films by changing the bending radii of the flexible substrates. The structural and thermoelectric properties of the completed samples were analyzed. It was found that the lattice parameters of all samples exhibited smaller values compared to that of standard data for Bi2Te3 (JCPDS 15-0863) because the substrates might have shrunk during the film deposition, indicated by the fact that all the samples presented various compressive lattice strains. A theoretical analysis was performed using the first-principles study based on density functional theory. We calculated the electronic band structures for Bi2Te3 with the different lattice strains and predicted the thermoelectric properties based on the semi-classical Boltzmann transport equation in the rigid band approximation. The lowest conduction band edge in the Bi2Te3 band structure narrowed as the compressive lattice strain increased, indicating that the effective mass became smaller. Finally, the experimentally measured thermoelectric properties were compared with those obtained by the calculation. It was found that the calculated results were in good agreement with the experimental results.

A review of the applications of polarized neutron reflectometry (PNR) for the investigation of quantum materials is provided. Recent studies of superconductors, strongly correlated oxides, hydrogen‐induced modifications, topological insulators and chiral magnets are highlighted. The PNR technique uses a quantum beam of spin‐polarized neutrons to measure the nanomagnetic structure of thin films and heterostructures, with a sensitivity to magnetization at the scale of 10–2000 emu cm−3 and a vertical spatial resolution of 1–500 nm. From simple beginnings studying the magnetic flux penetration at superconducting surfaces, today the PNR technique is widely used for investigating many different types of thin film structures, surfaces, interfaces, and 2D materials. PNR measurements can reveal a number of details about magnetic, electronic, and superconducting properties, in tandem with chemical information including the stoichiometry of light elements such as oxygen and hydrogen.

… conversion (CSC) efficiency at interfaces with ferromagnetic materials (FMs). This study focused … various heterostructures, according to results obtained from spin-torque ferromagnetic …

… semiconductor/ferromagnetic metal heterostructures, which is … The thicknesses of the Co2MnGa and Bi2Te3 layers were … between the Co2MnGa and Bi2Te3 layers were set to zero, …

… We report the epitaxial growth of MnTe/Bi 2 Te 3 heterostructures on BaF 2 (1 1 1), … electronic and magnetic excitations establishes MnTe/Bi 2 Te 3 heterostructures on BaF 2 (1 1 1) as a …

The rapid progress in 2D material research has triggered the growth of various quantum nanostructures- nanosheets, nanowires, nanoribbons, nanocrystals and the exotic nature originating through 2D heterostructures has extended the synthesis of hybrid materials beyond the conventional approaches. Here we introduce simple, one step confined thin melting approach to form nanostructures of TI (topological insulator) materials, their hybrid heterostructures with other novel 2D materials and their scalable growth. The substrate and temperature dependent growth is investigated on insulating, superconducting, metallic, semiconducting and ferromagnetic materials. The temperature dependent synthesis enables the growth of single, few quintuples to nanosheets and nanocrystals. The density of nanostructure growth is seen more on fabricated patterns or textured substrates. The fabricated nanostructure based devices show the broadband photodetection from ultraviolet to near infrared and exhibit high photoresponsivity. Ultimately, this unique synthesis process will give easy access to fabricate devices on user friendly substrates, study nanostructures and scalable growth will enable their future technology applications.

… heterostructures. For example, the generation of optical terahertz spin currents at room temperature has been demonstrated in 2D ferromagnetic Fe3GeTe2/Bi2Te3, … elastic peaks occur. …

Topological insulators (TIs) with spin-momentum-locked surface states and considerable spin-to-charge conversion (SCC) efficiency are ideal substitutes for the nonmagnetic layer in the traditional ferromagnetic/nonmagnetic (FM/NM) spintronic terahertz (THz) emitters. Here, the TI/ferrimagnetic structure as an effective polarization tunable THz source is verified by terahertz emission spectroscopy. The emitted THz electric field can be separated into two THz components utilizing their opposite symmetry on pump polarization and the magnetic field. TI not only emits a THz electric field via the linear photogalvanic effect (LPGE) but also serves as the medium of SCC via the inverse Edelstein effect (IEE) in the heterostructure. In addition, the amplitude and polarity of the SCC component can be efficiently manipulated by temperature in our ferrimagnetic TbFeCo layer compared with Co or Fe. Once these two THz components are delicately set orthogonally, an elliptical THz wave is generated by the intrinsic phase difference at the THz frequency range. The feasible control of its polarization and chirality is demonstrated by three means: pump polarization, magnetic field, and temperature. These appealing observations may pave the way for the development of elliptical THz wave emitters and polarization-sensitive THz spectroscopy.

Two-dimensional (2D) ferromagnetic materials are subjects of intense research owing to their intriguing physicochemical properties, which hold great potential for fundamental research and spintronic applications. Specifically, 2D van der Waals (vdW) ferromagnetic materials retain both structural integrity and chemical stability even at the monolayer level. Moreover, due to their atomic thickness, these materials can be easily manipulated by stacking them with other 2D vdW ferroic and nonferroic materials, enabling precise control over their physical properties and expanding their functional applications. Consequently, 2D vdW ferromagnetic materials-based heterostructures offer a platform to tailor magnetic properties and explore advanced spintronic devices. This review aims to provide an overview of recent developments in emerging 2D vdW ferromagnetic materials-based heterostructures and devices. The fabrication approaches for 2D ferromagnetic vdW heterostructures are primarily summarized, followed by a review of two categories of heterostructures: ferromagnetic/ferroic and ferromagnetic/nonferroic vdW heterostructures. Subsequently, the progress made in modulating magnetic properties and emergence of various phenomena in these heterostructures is highlighted. Furthermore, the applications of such heterostructures in spintronic devices are discussed along with their future perspectives and potential directions in this exciting field.

… When the temperature is very low, due to the weak scattering effect of phonons, elastic … , and it is difficult to induce long-range ferromagnetic order in MnTe. On the other hand, there are …

Layered 3d‐orbital ferromagnet is an ideal research platform to experimentally achieve intrinsic 2D ferromagnetism and theoretically study the quantum nature of magnetic exchange interactions therein. A variety of magnetic phases can emerge from the strongly correlated feature of 3d‐orbital electrons, in which their exchange interactions can be effectively modulated by various kinds of external stimuli. Therefore, controlling the emergent magnetic phenomena of layered 3d‐orbital ferromagnets is significant in both fundamental science and practical applications. Considering the roles of magnetic exchange interactions, this review summarizes recent progress in controlling the emergent magnetic properties of layered 3d‐orbital ferromagnets by systematically introducing modulation methods, underlying mechanisms, and device applications. The existing challenges and future prospects for this research field are also outlined, shedding light on finding optimized magnetic materials, exploring powerful modulation techniques, and designing multifunctional new concept devices.

… in the strength of spin–orbit coupling as we substitute Te by … indicating the presence of ferromagnetic state. Increasing … the ferromagnetism because we get a significant ferromagnetic …

The experimental realization of the quantum anomalous Hall (QAH) effect in magnetically-doped (Bi, Sb)2Te3 films stands out as a landmark of modern condensed matter physics. However, ultra-low temperatures down to few tens of mK are needed to reach the quantization of Hall resistance, which is two orders of magnitude lower than the ferromagnetic phase transition temperature of the films. Here, we systematically study the band structure of V-doped (Bi, Sb)2Te3 thin films by angle-resolved photoemission spectroscopy (ARPES) and show unambiguously that the bulk valence band (BVB) maximum lies higher in energy than the surface state Dirac point. Our results demonstrate clear evidence that localization of BVB carriers plays an active role and can account for the temperature discrepancy.

… jump contribution to the anomalous Hall effect. Our results provide … of scattering potentials and spin-orbit coupling. It has a linear … -optical Kerr effect measurements on Bi2Te3|FGT based …

The photoinduced anomalous Hall effect (PAHE) serves as a powerful probe for investigating topological band structures in quantum materials. While three-dimensional (3D) topological insulators (TIs) like Sb2Te3 exhibit promising spintronic properties, achieving effective modulation of their PAHE remains experimentally challenging. This study demonstrates strain-engineered control of PAHE in Sb2Te3 thin films with thicknesses ranging from 5 to 20 quintuple layers (QLs). Through systematic strain-dependent measurements, we reveal a non-monotonic thickness-mediated response: the PAHE current initially increases then decreases under uniaxial tensile strain across all studied thicknesses. Remarkably, the seven QL sample under 0.18% tensile strain exhibits a record-high photoinduced anomalous Hall conductivity of 1.88×103 m/(Ω· W) under 1064 nm illumination. Comprehensive analysis of strain-dependent sheet resistance (Rs), photoconductivity current (IPC) of the Si substrates, and circular photogalvanic effect (CPGE) current of the Sb2Te3 films on Si substrates, uncovers a strain-mediated mechanism governed by the synergistic effects of spin injection from Si substrates and strain-modulated spin–orbit coupling strength. Our findings demonstrate a viable strategy for manipulating quantum transport through strain engineering while providing insights into the interplay between mechanical deformation and topological electronic states.

We investigated the correlation between electrical transport and mechanical stress in a topological insulator, Bi2Te3, using conductive probe atomic force microscopy in an ultrahigh vacuum environment. After directly measuring charge transport on the cleaved Bi2Te3 surface, we found that the current density varied with applied load. Current mapping revealed a variation of the current on different terraces. The current density increased in the low-pressure regime and then decreased in the high-pressure regime. This variation of current density was explained in light of the combined effect of changes in the in-plane conductance due to spin–orbit coupling and hexagonal warping.

The quantized anomalous Hall effect (QAHE) have been theoretically predicted and experimentally confirmed in magnetic topological insulators (TI), but dissipative channels resulted by small-size band gap and weak ferromagnetism make QAHE be measured only at extremely low temperature (<0.1 K). Through density functional theory calculations, we systemically study of the magnetic properties and electronic structures of Mn doped Bi2Se3 with in-plane and out-of-plane strains. It is found that out-of-plane tensile strain not only improve ferromagnetism, but also enlarge Dirac-mass gap (up to 65.6 meV under 6% strain, which is higher than the thermal motion energy at room temperature ~26 meV) in the Mn doped Bi2Se3. Furthermore, the underlying mechanisms of these tunable properties are also discussed. This work provides a new route to realize high-temperature QAHE and paves the way towards novel quantum electronic device applications.

… compressive uniaxial strain, even without considering the spin-orbit coupling effect. This … the spin-orbit coupling effect but can also occur as a result of both scalar relativistic effects and …

ABSTRACT The interplay of the topology of electronic wavefunctions with spin configurations in intrinsically magnetic topological materials causes various exotic electronic states, attracting much attention in condensed matter physics. Non‐collinear antiferromagnetic (ncAFM) state, characterized by spins lacking a specific orientation, remains enigmatic. Through first‐principles calculations and Wannier simulations, we predicted that the AB‐stacked CoBi2Te4 two‐septuple layer (2SL) hosts an intrinsically intralayer ncAFM state while preserving a band inversion between Bi‐p and Te‐p orbitals in its bulk band structure. Intriguingly, we identified a group of flat bands near the Fermi level in the edge state of (210) nanoribbon terminated by ncAFM coupling. These flat bands persist in the edge state of a CoBi2Te4‐Bi2Te3 heterostructure, where intralayer ncAFM coupling is maintained. In contrast, they vanish in systems lacking either band inversion or ncAFM coupling. This suggests that the formation of flat bands arises from the interplay between spin‐orbit coupling–induced band inversion and the spatially varying local exchange field generated by intralayer ncAFM ordering. Our findings not only uncover the topological properties and electronic states of an intrinsically ncAFM configuration for the first time but also provide a novel strategy for realizing flat bands, which could have implications for strongly correlated electron systems.

… In WSe2–CrI3 heterostructures, external magnetic fields tune … exhibits high flexibility for magnetic heterostructures.The proximity… topological insulator Bi2Te3 through vdW forces. It has a …

A unique relaxation mechanism in wet‐chemically synthesized Bi2Te3–Sb2Te3 lateral heterostructures is presented, combining insights from molecular statics/dynamics simulations with a novel characterization technique based on STEM imaging using a defocused probe. The molecular simulations indicate that these heterostructures undergo intrinsic structural relaxation due to lattice mismatch and elastic anisotropy, resulting in uniform bending into dome‐shaped geometries with radii of curvature on the micron scale. While conventional bright‐field TEM imaging experimentally shows symmetric bend contours due to uniform bending, we demonstrate that defocused HAADF‐STEM produces unique contrast patterns sensitive to the sign of the probe defocus. This allows for the acquisition of crystallographic information (both magnitude and sign of curvature) in real space over large fields of view. The underlying physical mechanism is elucidated through scattering theory, focusing on the matching of the incident electron wave phase front with the local crystal lattice orientation and is supported by comprehensive dynamical multislice simulations of electron channeling maps. These findings are further validated by electron tomography and momentum‐resolved 4D‐STEM experiments. These insights are not only relevant for deciphering the local crystallographic properties of the Bi2Te3–Sb2Te3 system, but also establish a STEM‐based approach to characterize crystal bending across different zone axes in 2D nanostructures. This methodology provides a robust, real‐space alternative for analyzing intrinsic or strain‐induced curvature over large fields of view using unconventional HAADF‐STEM.

… , thermal expansion mismatch, bending, or interfacial … heterostructures have shown that structural transitions of the substrate can induce abrupt changes in the electrical or magnetic …

We acknowledge partial support from the Basque Country Government, Departamento de Educacion, Universidades e Investigacion (Grant No. IT-756-13), the Spanish Ministry of Science and Innovation (Grant No. FIS2016-75862-P), the Tomsk State University Academic D.I. Mendeleev Fund Program (Grant No. 8.1.05.2015), Saint Petersburg State University (Grant No. 15.61.202.2015), Russian Science Foundation (Grant No. 18-12-000169), and Russian Foundation for Basic Research (Grant No. 16-02-00024).

… (15−18,20−24,38−44) In the present study, the fabrication of vdW of bismuth telluride (Bi 2 Te … These three different 2D systems are considered to form heterostructures with the TM and …

Spintronics‐based magnetic random‐access memory (MRAM) represents a transformative leap in memory technology by harnessing both the spin and charge of an electrons for non‐volatile, high‐density, and ultrafast data storage. At the heart of MRAM lies the magnetic tunnel junction (MTJ), due to its cost‐effectiveness and scalability. Achieving high tunnel magnetoresistance (TMR) necessitates advanced fabrication techniques, precise material growth, and optimized device design. The advent of low‐dimensional materials (LDMs) such as 2D semiconductors (TMDs, graphene), insulators (h‐BN, MgO, BNNT), and magnetic materials (CrI3, Fe3GeTe2, MX3) has revolutionized MTJ design. These LDMs eliminate interfacial bonding, surface and internal defects issues that are inherently found in bulk counterparts enabling defect‐free structures, enhanced TMR ratio and room‐temperature operation. h‐BN as tunnel material and selection of electrode and barrier from the same family (e.g., SrRuO3/SrTiO3) mitigates lattice, conduction, and spin mismatch, while van der Waals (vdWs) heterostructures enhance spin injection efficiency. However, understanding the impact of doping, defects, and strain engineering on LDM‐MTJs performance requires deeper exploration. Despite significant advancements in MTJ technology, critical challenges persist in achieving high interfacial quality, scalable fabrication processes, and material stability under operational stress. This factor remains critical barriers for their widespread adoption, necessitating innovative solutions in future research.