Large Spin Hall Angle in Sputtered BiSb Topological Insulator on Top of Various Ferromagnets With In-Plane Magnetization for SOT Reader Application

A spin-orbit torque (SOT) reader using the inverse spin Hall effect was recently proposed as a candidate for magnetic recording beyond 4 Tbit/in(2). However, SOT readers using conventional heavy metals have small output voltage and low signal-to-noise ratio (SNR) due to the small spin Hall angles of heavy metals. Demonstrated in this work is a large spin Hall angle of 2.6-5.1 in sputtered BiSb, a topological insulator, on top of various ferromagnets with in-plane magnetization. The spin Hall angle of BiSb is much larger than that of heavy metals, which is promising for SOT readers with large output and high SNR.

Automated summary

A spin-orbit torque (SOT) reader using the inverse spin Hall effect was proposed for magnetic recording beyond 4 Tbit/in(2). However, conventional heavy metals have small spin Hall angles, resulting in low output voltage and SNR. This work demonstrated a large spin Hall angle of 2.6-5.1 in sputtered BiSb, a topological insulator, on various ferromagnets with in-plane magnetization, showing promise for SOT readers with high output and SNR.