Agarwal Piyush, Huang Lisen, Ter Lim Sze, Singh Ranjan
Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore.
Center for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, Singapore, 639798, Singapore.
Nat Commun. 2022 Jul 14;13(1):4072. doi: 10.1038/s41467-022-31789-0.
Energy-efficient spintronic technology holds tremendous potential for the design of next-generation processors to operate at terahertz frequencies. Femtosecond photoexcitation of spintronic materials generates sub-picosecond spin currents and emission of terahertz radiation with broad bandwidth. However, terahertz spintronic emitters lack an active material platform for electric-field control. Here, we demonstrate a nonlinear electric-field control of terahertz spin current-based emitters using a single crystal piezoelectric Pb(MgNb)O-PbTiO (PMN-PT) that endows artificial magnetoelectric coupling onto a spintronic terahertz emitter and provides 270% modulation of the terahertz field at remnant magnetization. The nonlinear electric-field control of the spins occurs due to the strain-induced change in magnetic energy of the ferromagnet thin-film. Results also reveal a robust and repeatable switching of the phase of the terahertz spin current. Electric-field control of terahertz spintronic emitters with multiferroics and strain engineering offers opportunities for the on-chip realization of tunable energy-efficient spintronic-photonic integrated platforms.
节能自旋电子技术在设计运行于太赫兹频率的下一代处理器方面具有巨大潜力。对自旋电子材料进行飞秒光激发会产生亚皮秒自旋电流并发射具有宽带宽的太赫兹辐射。然而，太赫兹自旋电子发射器缺乏用于电场控制的活性材料平台。在此，我们展示了基于太赫兹自旋电流的发射器的非线性电场控制，该控制使用了单晶压电材料Pb(MgNb)O-PbTiO（PMN-PT），它将人工磁电耦合赋予自旋电子太赫兹发射器，并在剩余磁化强度下实现了太赫兹场270%的调制。自旋的非线性电场控制是由于铁磁薄膜磁能的应变诱导变化而产生的。结果还揭示了太赫兹自旋电流相位的稳健且可重复切换。利用多铁性材料和应变工程对太赫兹自旋电子发射器进行电场控制，为片上实现可调谐节能自旋电子-光子集成平台提供了机会。
