물리학과

Title : Electrical manipulation of magnetization driven by self-generated spin torque

일시 : 2026년 5월 26일 (화), 17시 

장소 : 아산이학관 433호

Speaker : 김경환 (연세대학교 물리학과)

Abstracts:

Magnetism is a core quantum mechanical phenomenon with a profound impact on modern life. In information technology, the measurement and manipulation of magnetic states remain critical objectives with broad fundamental and practical implications. In the first part of my talk, I will review methods for electrically measuring and manipulating magnetization via the electron’s spin degree of freedom, and discuss how this approach has driven significant advancements in modern technology. Specifically, I will highlight spin-transfer torque and spin-orbit torque, which are effective mechanisms for controlling magnetization relying on the exchange interaction and spin-orbit coupling, respectively.

Building upon these conventional approaches, the second part of my talk introduces a new paradigm centered on magnon dissipation. While conventional strategies aim to minimize magnetic dissipation to enhance transport, we propose a novel approach that leverages magnon dissipation itself as an active mechanism for magnetization control. By interfacing a single ferromagnetic metal with an antiferromagnetic insulator, we observe a sizable spin-orbit torque, comparable to those in heavy non-magnetic metals, and sufficient to induce magnetization switching. Through systematic experiments and detailed analysis, we demonstrate that these spin torques arise intrinsically from magnonic spin dissipation without the need for external spin sources. Our findings shed new light on the elusive nature of intrinsic spin currents in ferromagnets and present a promising route toward energy-efficient spintronic devices driven by controlled magnon dissipation.