Kobecki Michal, Scherbakov Alexey V, Linnik Tetiana L, Kukhtaruk Serhii M, Gusev Vitalyi E, Pattnaik Debi P, Akimov Ilya A, Rushforth Andrew W, Akimov Andrey V, Bayer Manfred
Experimentelle Physik 2, Technische Universität Dortmund, Otto-Hahn-Strasse 4a, 44227, Dortmund, Germany.
Ioffe Institute, Politechnycheskaya 26, St. Petersburg, Russian Federation, 194021.
Nat Commun. 2020 Aug 17;11(1):4130. doi: 10.1038/s41467-020-17635-1.
Energy harvesting is a concept which makes dissipated heat useful by transferring thermal energy to other excitations. Most of the existing principles are realized in systems which are heated continuously. We present the concept of high-frequency energy harvesting where the dissipated heat in a sample excites resonant magnons in a thin ferromagnetic metal layer. The sample is excited by femtosecond laser pulses with a repetition rate of 10 GHz, which results in temperature modulation at the same frequency with amplitude ~0.1 K. The alternating temperature excites magnons in the ferromagnetic nanolayer which are detected by measuring the net magnetization precession. When the magnon frequency is brought onto resonance with the optical excitation, a 12-fold increase of the amplitude of precession indicates efficient resonant heat transfer from the lattice to coherent magnons. The demonstrated principle may be used for energy harvesting in various nanodevices operating at GHz and sub-THz frequency ranges.
能量收集是一个通过将热能转移到其他激发态来使耗散热量变得有用的概念。现有的大多数原理都是在持续加热的系统中实现的。我们提出了高频能量收集的概念，其中样品中的耗散热量会激发薄铁磁金属层中的共振磁振子。样品由重复频率为10 GHz的飞秒激光脉冲激发，这会导致相同频率下幅度约为0.1 K的温度调制。交变温度会激发铁磁纳米层中的磁振子，通过测量净磁化进动来检测这些磁振子。当磁振子频率与光激发达到共振时，进动幅度增加12倍表明从晶格到相干磁振子的高效共振热传递。所展示的原理可用于在GHz和亚太赫兹频率范围内运行的各种纳米器件中的能量收集。
