[20a-B101-1~10] 10.3 スピンデバイス・磁気メモリ・ストレージ技術

▼ [20a-B101-1] Giant inverse spin Hall effect in BiSb topological insulator-based SOT reader

〇(M2)HOANGHUY HO¹、SASAKI J.¹、KHANG N. H. D.¹、NAMHAI Pham¹、Q. LE²、B. YORK²、X. LIU²、M. GRIBELYUK²、X. XU²、S. LE²、M. HO²、H. TAKANO² (1.Tokyo Tech.、2.Western Digital Inc.)

キーワード：spin-orbit torque, BiSb, magnetic field sensor

Scaling of TMR reader for magnetic recording beyond 4 Tb/in² encounters increasing difficulties due to its complex film stack and increase of noise. Recently, a spin-orbit torque (SOT) reader employing the inverse spin Hall effect was introduced to solve these problems. However, the output voltage and signal-to-noise ratio (SNR) of SOT reader using heavy metals as the SOT layer are insufficient due to small spin Hall angle (SHA) and low sheet resistance of heavy metals. Topological insulator (TI) BiSb is promising candidate to enhance the output signal and SNR thanks to its giant SHA and larger sheet resistance.
In this work, we demonstrate a proof-of-concept for a BiSb-based SOT reader with large output voltage and SNR. The output is as large as 15 mV, which is 3 orders of magnitude larger than that of Pt-based devices. We project a giant inverse spin Hall angle of 24 for this device, which demonstrates the potential of BiSb for SOT reader application.