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Measurement of 3D vector magnetic field is of vital importance for the development of magnetic navigation, biomedical diagnosis, and microimaging. Traditional 3D magnetic sensors require cooperation of multiple sensors on three orthogonal planes, resulting in disadvantages of bulky size and low spatial resolution. Recently proposed spin orbit torque sensor based on ferromagnetic/heavy‐metal heterostructures can detect three magnetic field components individually due to the different symmetries of current‐polarity‐dependent magnetization dynamic. However, the large driving current density and complex driving procedure hinder their practical application, especially in AC magnetic field detection. Herein, 3D magnetic sensors with dramatically reduced driving current density are reported, one fifth of the original value, by exquisite engineering of the magnetic anisotropy in Pt/Co/Ta heterostructures. With further reduced perpendicular magnetic anisotropy, the sensor in the easy‐cone state demonstrates a record‐high sensitivity of 31196 V A−1 T−1. More importantly, the easy‐cone state sensor can work with an ultralow driving current density of 3.8 kA cm−2, which is three orders lower than previous results. Although easy‐cone state sensor can only measure the z‐axis field, highly compact 3D magnetic sensor can be realized by adoption of two anisotropic magnetoresistance sensors, promising great potential application in space‐ and energy‐restricted scenarios. [ABSTRACT FROM AUTHOR]

Magnetization dynamics induced by spin–orbit torques in a heavy‐metal/ferromagnet can potentially be used to design low‐power spintronics and logic devices. Recent computations have suggested that a strain‐mediated spin–orbit torque (SOT) switching in magnetoelectric (ME) heterostructures is fast, energy‐efficient, and permits a deterministic 180° magnetization switching. However, its experimental realization has remained elusive. Here, the coexistence of the strain‐mediated ME coupling and the SOT in a CoFeB/Pt/ferroelectric hybrid structure is shown experimentally. The voltage‐induced strain only slightly modifies the efficiency of SOT generation, but it gives rise to an effective magnetic anisotropy and rotates the magnetic easy axis which eliminates the incubation delay in current‐induced magnetization switching. The phase field simulations show that the electric‐field‐induced effective magnetic anisotropy field can reduce the switching time approximately by a factor of three for SOT in‐plane magnetization switching. It is anticipated that such strain‐mediated ME‐SOT hybrid structures may enable field‐free, ultrafast magnetization switching. A strain‐mediated magnetoelectric‐spin‐torque hybrid structure, which combines the advantages of spin orbit torque‐ and magnetoelectric‐ driven magnetization dynamics together, is developed. Via a magentoelectric effect, voltage‐controlled magnetic anisotropy is demonstrated in spin–orbit torque devices, which can lead to a reduction of the magnetization switching time by a factor of three. The findings provide a new platform for fast and low‐power spintronics. [ABSTRACT FROM AUTHOR]

Ferromagnetic insulator thin film nanostructures are becoming the key component of the state‐of‐the‐art spintronic devices, for instance, yttrium iron garnet (YIG) with low damping, high Curie temperature, and high resistivity is explored into many spin–orbit interactions related spintronic devices. Voltage modulation of YIG, with great practical/theoretical significance, thus can be widely applied in various YIG‐based spintronics effects. Nevertheless, to manipulate ferromagnetism of YIG through electric field (E‐field), instead of current, in an energy efficient manner is essentially challenging. Here, a YIG/Cu/Pt layered nanostructure with a weak spin–orbit coupling interaction is fabricated, and then the interfacial magnetism of the Cu and YIG is modified via ionic liquid gating method significantly. A record‐high E‐field‐induced ferromagnetic resonance field shift of 1400 Oe is achieved in YIG (17 nm)/Cu (5 nm)/Pt (3 nm)/ionic liquid/Au capacitor layered nanostructures with a small voltage bias of 4.5 V. The giant magnetoelectric tunability comes from voltage‐induced extra ferromagnetic ordering in Cu layer, confirmed by the first‐principle calculation. This E‐field modulation of interfacial magnetism between light metal and magnetic isolator may open a door toward compact, high‐performance, and energy‐efficient spintronic devices. A record‐high E‐field‐induced ferromagnetic resonance field shift of 1400 Oe is achieved in an yttrium iron garnet/Cu/Pt/ionic liquid/Au capacitor heterostructure with a small voltage bias of 4.5 V characterized via in situ electron spin resonance spectroscopy. The giant magnetoelectric tunability comes from voltage‐induced extra ferromagnetic ordering in the Cu layer, confirmed by the first‐principle calculation. [ABSTRACT FROM AUTHOR]