7 research outputs found
Electric-field-induced formation and annihilation of skyrmions in two-dimensional magnet
Electric manipulation of skyrmions in 2D magnetic materials has garnered
significant attention due to the potential in energy-efficient spintronic
devices. In this work, using first-principles calculations and Monte Carlo
simulations, we report the electric-field-tunable magnetic skyrmions in
MnIn2Te4 monolayer. By adjusting the magnetic parameters, including the
Heisenberg exchange interaction, DMI, and MAE, through applying an electric
field, the formation or annihilation of skyrmions can be achieved. Our work
suggests a platform for experimental realization of the electric-field-tunable
magnetic skyrmions in 2D magnets
Strong in-plane magnetic anisotropy (Co0.15Fe0.85)5GeTe2/graphene van der Waals heterostructure spin-valve at room temperature
Van der Waals (vdW) magnets are promising owing to their tunable magnetic
properties with doping or alloy composition, where the strength of magnetic
interactions, their symmetry, and magnetic anisotropy can be tuned according to
the desired application. However, most of the vdW magnet based spintronic
devices are so far limited to cryogenic temperatures with magnetic anisotropies
favouring out-of-plane or canted orientation of the magnetization. Here, we
report room-temperature lateral spin-valve devices with strong in-plane
magnetic anisotropy of the vdW ferromagnet (Co0.15Fe0.85)5GeTe2 (CFGT) in
heterostructures with graphene. Magnetization measurements reveal above
room-temperature ferromagnetism in CFGT with a strong in-plane magnetic
anisotropy. Density functional theory calculations show that the magnitude of
the anisotropy depends on the Co concentration and is caused by the
substitution of Co in the outermost Fe layer. Heterostructures consisting of
CFGT nanolayers and graphene were used to experimentally realize basic building
blocks for spin valve devices such as efficient spin injection and detection.
The spin transport and Hanle spin precession measurements prove a strong
in-plane and negative spin polarization at the interface with graphene, which
is supported by the calculated spin-polarized density of states of CFGT. The
in-plane magnetization of CFGT at room temperature proves its usefulness in
graphene lateral spin-valve devices, thus opening further opportunities for
spintronic technologies
Making Atomic-Level Magnetism Tunable with Light at Room Temperature
The capacity to manipulate magnetization in two-dimensional dilute magnetic
semiconductors (2D-DMSs) using light, specifically in magnetically doped
transition metal dichalcogenide (TMD) monolayers (M-doped TX2, where M = V, Fe,
Cr; T = W, Mo; X = S, Se, Te), may lead to innovative applications in
spintronics, spin-caloritronics, valleytronics, and quantum computation. This
Perspective paper explores the mediation of magnetization by light under
ambient conditions in 2D-TMD DMSs and heterostructures. By combining magneto-LC
resonance (MLCR) experiments with density functional theory (DFT) calculations,
we show that the magnetization can be enhanced using light in V-doped TMD
monolayers (e.g., V-WS2, V-WSe2, V-MoS2). This phenomenon is attributed to
excess holes in the conduction and valence bands, as well as carriers trapped
in magnetic doping states, which together mediate the magnetization of the
semiconducting layer. In 2D-TMD heterostructures such as VSe2/WS2 and
VSe2/MoS2, we demonstrate the significance of proximity, charge-transfer, and
confinement effects in amplifying light-mediated magnetism. This effect is
attributed to photon absorption at the TMD layer (e.g., WS2, MoS2) that
generates electron-hole pairs mediating the magnetization of the
heterostructure. These findings will encourage further research in the field of
2D magnetism and establish a novel direction for designing 2D-TMDs and
heterostructures with optically tunable magnetic functionalities, paving the
way for next-generation magneto-optic nanodevices
New Research Trends in Electrically Tunable 2D van der Waals Magnetic Materials
The recent discovery of two-dimensional (2D) van der Waals (vdW) magnetic
materials has provided new, unprecedented opportunities for both fundamental
science and technological applications. Unlike three-dimensional (3D) magnetic
systems, the electric manipulation of vdW magnetism (e.g., magnetization state,
magnetic anisotropy, magnetic ordering temperature) down to the monolayer limit
at ambient conditions enables high efficiency operation and low energy
consumption, which has the potential to revolutionize the fields of
spintronics, spin-caloritronics, and valleytronics. This article provides an
in-depth analysis of the recent progress, emerging opportunities, and technical
challenges in the electric manipulation of magnetic functionalities of a wide
variety of 2D vdW magnetic systems ranging from metals to semiconductors and
heterostructures. The state-of-the-art understanding of the mechanisms behind
the electric modulation of magnetism in these 2D vdW magnetic systems will
drive future research towards novel applications in spintronics,
spin-caloritronics, valleytronics, and quantum computation
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A Van der Waals Interface Hosting Two Groups of Magnetic Skyrmions.
Multiple magnetic skyrmion phases add an additional degree of freedom for skyrmion-based ultrahigh-density spin memory devices. Extending the field to 2D van der Waals magnets is a rewarding challenge, where the realizable degree of freedoms (e.g., thickness, twist angle, and electrical gating) and high skyrmion density result in intriguing new properties and enhanced functionality. In this work, a van der Waals interface, formed by two 2D ferromagnets Cr2 Ge2 Te6 and Fe3 GeTe2 with a Curie temperature of â65 and â205 K, respectively, hosting two groups of magnetic skyrmions, is reported. Two sets of topological Hall effect signals are observed below 6s0 K when Cr2 Ge2 Te6 is magnetically ordered. These two groups of skyrmions are directly imaged using magnetic force microscopy, and supported by micromagnetic simulations. Interestingly, the magnetic skyrmions persist in the heterostructure with zero applied magnetic field. The results are promising for the realization of skyrmionic devices based on van der Waals heterostructures hosting multiple skyrmion phases
A Van der Waals Interface Hosting Two Groups of Magnetic Skyrmions
Multiple magnetic skyrmion phases add an additional degree of freedom for skyrmion-based ultrahigh-density spin memory devices. Extending the field to 2D van der Waals magnets is a rewarding challenge, where the realizable degree of freedoms (e.g., thickness, twist angle, and electrical gating) and high skyrmion density result in intriguing new properties and enhanced functionality. In this work, a van der Waals interface, formed by two 2D ferromagnets Cr2 Ge2 Te6 and Fe3 GeTe2 with a Curie temperature of â65 and â205 K, respectively, hosting two groups of magnetic skyrmions, is reported. Two sets of topological Hall effect signals are observed below 6s0 K when Cr2 Ge2 Te6 is magnetically ordered. These two groups of skyrmions are directly imaged using magnetic force microscopy, and supported by micromagnetic simulations. Interestingly, the magnetic skyrmions persist in the heterostructure with zero applied magnetic field. The results are promising for the realization of skyrmionic devices based on van der Waals heterostructures hosting multiple skyrmion phases