All-optical observation and reconstruction of spin wave dispersion

作者：Hashimoto Yusuke; Daimon Shunsuke; Iguchi Ryo; Oikawa Yasuyuki; Shen Ka; Sato Koji; Bossini Davide; Tabuchi Yutaka; Satoh Takuya; Hillebrands Burkard; Bauer Gerrit E W; Johansen Tom H; Kirilyuk Andrei; Rasing Theo; Saitoh Eiji

来源：Nature Communications, 2017, 8(1): 15859.

DOI：10.1038/ncomms15859

To know the properties of a particle or a wave, one should measure how its energy changes with its momentum. The relation between them is called the dispersion relation, which encodes essential information of the kinetics. In a magnet, the wave motion of atomic spins serves as an elementary excitation, called a spin wave, and behaves like a fictitious particle. Although the dispersion relation of spin waves governs many of the magnetic properties, observation of their entire dispersion is one of the challenges today. Spin waves whose dispersion is dominated by magnetostatic interaction are called pure-magnetostatic waves, which are still missing despite of their practical importance. Here, we report observation of the band dispersion relation of pure-magnetostatic waves by developing a table-top all-optical spectroscopy named spin-wave tomography. The result unmasks characteristics of pure-magnetostatic waves. We also demonstrate time-resolved measurements, which reveal coherent energy transfer between spin waves and lattice vibrations.

• 出版日期2017-6-12