Yonghai Guo

Lanzhou University | LZU · School of Physical Science and Technology

Spin–orbit torque provides an efficient strategy for electric manipulation of magnetization. However, Joule heat accompanying with electron motion in the electron-mediated spin current result in unavoidable power dissipation. Moreover, the spin diffusion length in electron-mediated spin current is relatively short, preventing the transmission of sp...

Seeking the magnetic heterostructures with large current-induced torque efficiency is currently one of the core hotspots in spintronics. In this work, we report the large and composition-dependent damping-like (DL) torque in the structure consisting of light metal Cr and Ti layers and a ferrimagnetic Tb–Co layer. The DL torque efficiency in the str...

A giant magnetoresistance (GMR) sensor with a Wheatstone bridge structure and an out-of-plane linear response was developed. The spin-valve structure consists of a synthetic antiferromagnetic [(Co/Pt) n /Ru/(Pt/Co) n ] reference layer with perpendicular magnetic anisotropy, a Cu spacer layer, and a Co-free layer with in-plane easy magnetization. By...

Spintronic devices can realize multi‐state storage and be used to simulate artificial synapses or artificial neurons, which makes them have promising application prospect in the field of artificial neural networks (ANN). This work investigates the current‐induced magnetization reversal in stacked (Ta/CoFeB/MgO)N structures and their application in...

The conventional spin-orbit torque (SOT) and magnetoresistance effect observed in normal-metal (NM)/ferromagnet (FM) bilayers originate from the interaction between magnetic moments and spin with in-plane transverse polarization (σ̂y). In FM/NM/FM trilayer structures, the presence of an extra FM layer breaks the symmetry, resulting in spin polariza...

The interaction between spin current and magnetic moments in heavy metal (HM)/ferromagnetic (FM) structure results in the well-known spin orbit torque and the concomitant magnetoresistance effect: spin Hall magnetoresistance (SMR) and the unidirectional SMR (USMR). In this work, we simultaneously investigated the SMR and USMR in Ta/Pt/CoFeB/MgO mul...

We investigated the ferromagnet (FM) and heavy metal (HM) thickness dependence of the electric current-induced spin orbit torque (SOT), especially the field-like (FL) torque component in HM/CoFeB/MgO heterostructures. For Pt/CoFeB/MgO and Ta/CoFeB/MgO structures, after subtracting the dead-layer thickness of CoFeB, the damping-like (DL) effective f...

We investigate a current-induced magnetization reversal process mediated by spin–orbit torque (SOT) in Ta/Pt/(Co/Ni) n Co/Ta multilayers experimentally and by micromagnetic simulation. Experimental results show that the current-induced magnetization reversal in these samples is completed by nucleation and subsequent domain wall (DW) propagation. Fo...

Current-induced magnetization switching in compensated ferrimagnetic materials by the spin–orbit torque (SOT) effect is promising for the next generation information storage devices. In this work, we report the current-induced deterministic field-free magnetization switching of the perpendicular Tb-Co ferrimagnet layer in a Co/Ti/Tb-Co trilayers. W...

Spintronic devices can realize multilevel state storage and mimic the properties of the synapse, which enables their potential application in the field of artificial neural networks. In this paper, we demonstrate the existence of a large intermediate transition zone in current-induced magnetization switching curves of Pt/Co–Tb/Ta structures, and th...

Although transition metal (TM)-rare earth (RE) alloy film has potential application as an information storage medium in spintronic devices, study of the physical mechanism and microscopic process for the current-induced magnetization switching by spin–orbit torque (SOT) in TM-RE is still inadequate. In this work, we investigated the SOT effect and...

The microscopic mechanism for the current-induced spin–orbit torque (SOT) in magnetic heterostructures is still under debate. The accurate measurement of SOT effective fields and their thickness dependence is the basis for understanding this issue. In this work, we measured the SOT effective fields for Pt/NiFe bilayers by utilizing the harmonic lon...