Electrical detection of magnetization dynamics via spin rectification effects

Abstract

The purpose of this article is to review the current status of a frontier in dynamic spintronics and contemporary magnetism, in which much progress has been made in the past decade, based on the creation of a variety of micro-and nano-structured devices that enable electrical detection of magnetization dynamics. The primary focus is on the physics of spin rectification effects, which are well suited for studying magnetization dynamics and spin transport in a variety of magnetic materials and spintronic devices. Intended to be intelligible to a broad audience, the paper begins with a pedagogical introduction, comparing the methods of electrical detection of charge and spin dynamics in semiconductors and magnetic materials respectively. After that it provides a comprehensive account of the theoretical study of both the angular dependence and line shape of electrically detected ferromagnetic resonance (FMR), which is summarized in a handbook formate easy to be used for analyzing experimental data. We then review and examine the similarity and differences of various spin rectification effects found in ferromagnetic films, magnetic bilayers and magnetic tunnel junctions, including a discussion of how to properly distinguish spin rectification from the spin pumping/inverse spin Hall effect generated voltage. After this we review the broad applications of rectification effects for studying spin waves, nonlinear dynamics, domain wall dynamics, spin current, and microwave imaging. We also discuss spin rectification in ferromagnetic semiconductors. The paper concludes with both historical and future perspectives, by summarizing and comparing three generations of FMR spectroscopy which have been developed for studying magnetization dynamics.

Inverse Spin Hall Effect in Electron Beam Evaporated Topological Insulator Bi2Se3 Thin Film

“…It has been reported that the proper separation of the rectification effect from spin pumping can be analyzed by the angular dependence of the voltage . Therefore, we performed the in‐plane angle‐dependent measurements of the voltage at the interval of the 3° between the applied magnetic field and rf field ( φ ).…”

“…Therefore, we performed the in‐plane angle‐dependent measurements of the voltage at the interval of the 3° between the applied magnetic field and rf field ( φ ). In order to separate the various components of other galvanometric effects like AMR and AHE we employed the model given by Harder et al and in a recent report by A. Conca et al As per this model, the authors considered these two components of spin rectifications effects i.e., AMR perpendicular and parallel to the rf‐field and AHE. The expression for measured voltage can be written as …”

Spin Rectification dc Voltage Spectra via Sweeping Frequency

“…Further studies have even found that dc current and dc voltage can be generated by the rectification effect of high‐frequency magnetization dynamics. This so‐called spin rectification effect (SRE), which is due to nonlinear coupling between an oscillating current and an oscillating resistance in magnetic structures, provides a novel technique for the study of magnetization dynamics by electrical detection. Due to its high sensitivity and feasibility, the SRE has been widely employed to study ferromagnetic resonance (FMR), spin wave resonance, and domain‐wall resonance in different ferromagnetic materials.…”

“…Usually, a dc voltage spectrum was measured by sweeping the bias field at a fixed frequency. By solving the LLG equation, the spectrum can be fitted by the Lorentz and dispersive shape components, and the Lorentz shape is symmetric while the dispersive shape is antisymmetric around the resonance field . However, this method is not suitable if the magnetic domain structure changes with the sweeping of magnetic field during the measurement process, such as in stripe domain structure, in which the magnetic domains will reorientate along the external magnetic field .…”

Spin to Charge Conversion at the Conducting TiO2Surface

“…Frequency‐dependent voltage is a convenient way to characterize the magnetization dynamics . In Figure (a), the red solid curve denotes the V IREE extracted through the method of sample flipping at different frequencies of the microwave, and the varying magnitude of the V IREE arises from the variation of the phase between the microwave current and magnetization, which is determined by the sample and its holders.…”