Spin orbit torques(SOTs) in ferromagnet/heavy-metal heterostructures have provided great opportunities for efficient manipulation of spintronic devices. However, deterministically field-free switching of perpendicular magnetization with SOTs is forbidden because of the global two-fold rotational symmetry in conventional heavy-metal such as Pt. Here,we engineer the interface of Pt/Ni heterostructures by inserting a monolayer MoTe_2 with low crystal symmetry. It is demonstrated that the spin orbit efficiency, as well as the out-of-plane magnetic anisotropy and the Gilbert damping of Ni are enhanced, due to the effect of orbital hybridization and the increased spin scatting at the interface induced by MoTe_2.Particularly, an out-of-plane damping-like torque is observed when the current is applied perpendicular to the mirror plane of the MoTe_2 crystal, which is attributed to the interfacial inversion symmetry breaking of the system. Our work provides an effective route for engineering the SOT in Pt-based heterostructures, and offers potential opportunities for van der Waals interfaces in spintronic devices. 相似文献
ABSTRACTIn this work, we report the results of DC susceptibility, AC susceptibility and related technique, resistivity, transverse and longitudinal magnetoresistance and heat capacity on polycrystalline magnetic semimetal CeAlGe. This compound undergoes antiferromagnetic type ordering around 5.2 K (T1). Under the application of external magnetic fields, parallel alignment of magnetic moments is favoured above 0.5?T. At low field and temperature, frequency and AC field amplitude response of AC susceptibility indicate the presence of spin–lattice relaxation phenomena. The observation of spin–lattice interaction suggests the presence of the Rashba–Dresselhaus spin–orbit interaction which is associated with inversion and time-reversal symmetry breaking. Additionally, the presence of negative and asymmetric longitudinal magnetoresistance indicates anomalous velocity contribution to the magnetoresistance due to the Rashba–Dresselhaus spin–orbit interaction which is further studied by heat capacity. 相似文献
We study the spin ordering of a quantum dot defined via magnetic barriers in an interacting quantum spin Hall edge. The spin‐resolved density–density correlation functions are computed. We show that strong electron interactions induce a ground state with a highly correlated spin pattern. The crossover from the liquid‐type correlations at weak interactions to the ground state spin texture found at strong interactions parallels the formation of a one‐dimensional Wigner molecule in an ordinary strongly interacting quantum dot.
We investigate the equilibrium spin transport in a ferromagnet/noncentrosymmetric superconductor (FM/NCS) junction where the NCS has a dominant triplet order parameter and helical edge state. Based on the symmetry analysis and numerical calculation, we demonstrate that there is a nonzero spin supercurrent flowing in the junction, which stems from the exchange coupling between the FM magnetization and triplet Cooper-pair spin. It is also found that a transverse spin current other than the helical edge spin current is flowing along the interface of the junction, and its polarization is related to the longitudinal spin supercurrent. Besides, an equilibrium Hall current is also shown to flow along the junction’s interface due to the broken time-reversal symmetry from the FM. 相似文献
Ballistic spin transport in spin field-effect transistors is studied by taking into account the Rashba spinorbit coupling, interracial scattering, and band mismatch. It is shown that the spin conductance oscillation with the semiconductor channel length is a superimposition of the Rashba spin precession and spin interference oscillations. They have different oscillation periods π/κR and π/κ with κR the Rashba wavevector and κ the Fermi wavevector of the semiconductor channel, and play different parts of slow and rapid oscillations, depending upon the relative magnitude of π/κR and π/κ. Only at κ = κR does the spin conductance exhibit oscillations of a single period. Two types of different behaviors of the tunnelling magnetoresistance are discussed. 相似文献
Recent data on the bias dependence of the spin transfer effect in magnetic tunnel junctions have shown that torque remains intact at bias voltages for which the tunneling magnetoresistance has been strongly reduced. We show that the current induced excitations due to hot electrons, while reducing the magnetoresistance, enhance both the charge current and the spin transfer in magnetic tunnel junctions in such a manner that the ratio of the torque to the charge current does not significantly change. 相似文献
The effect of spin polarization of electrons injected from a ferromagnet on the giant injection magnetoresistance was investigated for a ferromagnet-polymer-nonmagnetic metal experimental structure. The degree of spin polarization was varied by introducing a depolarizing nonmagnetic metal (Cu) layer between the ferromagnet and the organic transport layer. It was established that the coefficient of giant injection magnetoresistance depends significantly on the thickness of the depolarizing layer. In particular, the effect was not observed at a thickness larger than 12 nm and decreased exponentially at a smaller thickness as the thickness increased. The conclusion was drawn that the spin polarization of electrons plays a decisive role in the effect of giant injection magnetoresistance. 相似文献
The spin‐dependent transport properties, including spin polarization and spin‐flip for phosphorene superlattice in the presence of an extrinsic Rashba spin‐orbit interaction (RSOI) based on the transfer matrix method, are studied. The results show that the number of barriers in the superlattice structure plays a dominant role in output spin polarization, which can be used in designing optimized spintronic devices. In addition, by controlling on the Rashba strength, an incident spin‐up electron can be transmitted as a spin‐down electron. Also, it enables to convert the unpolarized incident electronic beam (with zero spin polarization) into an arbitrary output spin polarization, which plays a significant role in qubit circuits. 相似文献
We report resistivity and Hall effect measurements in electron-doped Pr2-xCexCuO4-delta films in magnetic field up to 58 T. In contrast to hole-doped cuprates, we find a surprising nonlinear magnetic field dependence of Hall resistivity at high field in the optimally doped and overdoped films. We also observe a crossover from quadratic to linear field dependence of the positive magnetoresistance in the overdoped films. A spin density wave induced Fermi surface reconstruction model can be used to qualitatively explain both the Hall effect and magnetoresistance. 相似文献
Electron spin-polarization modulation with a ferromagnetic strip of in-plane magnetization is analyzed in a hybrid ferromagnet/semiconductor filter device.The dependencies of electron spin-polarization on the strip’s magnetization strength,width and position have been systematically investigated.A novel magnetic control spin-polarization switch is proposed by inserting a ferromagnetic metal(FM)strip eccentric in relation to off the center of the spin filter,which produces the first energy level spin-polarization reversal.It is believed to be of significant importance for the realization of semiconductor spintronics multiple-value logic devices. 相似文献
We study the spin polarized transport through a quantum dot transistor. It is shown that the interplay of large Coulomb interaction and optically induced spin accumulation gives rise to the spin valve effect over a range of bias. We also find negative tunnel magnetoresistance for system with ferromagnetic electrodes. 相似文献