Observing differential spin currents by resonant inelastic X-ray scattering

• 成果类型: Article
• 署名作者: Gu, Yanhong; Barker, Joseph; Li, Jiemin; Kikkawa, Takashi; Camino, Fernando; Kisslinger, Kim; Sinsheimer, John; Lienhard, Lukas; Bauer, Jackson J.; Ross, Caroline A.; Basov, Dmitri N.; Saitoh, Eiji; Pelliciari, Jonathan; Bauer, Gerrit E. W.; Bisogni, Valentina
• 署名单位: United States Department of Energy (DOE); Brookhaven National Laboratory; University of Leeds; University of Leeds; Tohoku University; Japan Atomic Energy Agency; United States Department of Energy (DOE); Brookhaven National Laboratory; Massachusetts Institute of Technology (MIT); Columbia University; University of Tokyo; University of Tokyo; Tohoku University; RIKEN
• 刊物名称: NATURE
• ISSN/ISSBN: 0028-0836; 1476-4687
• DOI: 10.1038/s41586-025-09488-9
• 发表日期: 2025-09-25
• 关键词: dynamics

摘要

Controlling spin currents, that is, the flow of spin angular momentum, in small magnetic devices, is the principal objective of spin electronics, a main contender for future energy-efficient information technologies1,2. A pure spin current has never been measured directly because the associated electric stray fields and/or shifts in the non-equilibrium spin-dependent distribution functions are too small for conventional experimental detection methods optimized for charge transport3,4. Here we report that resonant inelastic X-ray scattering (RIXS) can bridge this gap by measuring the spin current carried by magnons-the quanta of the spin wave excitations of the magnetic order-in the presence of temperature gradients across a magnetic insulator. This is possible due to the sensitivity of the momentum- and energy-resolved RIXS intensity to minute changes in the magnon distribution under non-equilibrium conditions. We use the Boltzmann equation in the relaxation time approximation to extract transport parameters, such as the magnon lifetime at finite momentum, essential for the realization of magnon spintronics.