退火效应增强铁磁异质结太赫兹发射实验及机理  

Annealing effect on terahertz emission enhancement from ferromagnetic heterostructures

作　　者：高扬 Chandan Pandey 孔德胤 王春 聂天晓 赵巍胜 苗俊刚[1] 汪力[3] 吴晓君 Gao Yang;Chandan Pandey;Kong De-Yin;Wang Chun;Nie Tian-Xiao;Zhao Wei-Sheng;Miao Jun-Gang;Wang Li;Wu Xiao-Jun(School of Electronic and Information Engineering,Beihang University,Beijing 100191,China;Beijing Advanced Innovation Certer for Big Data and Brain Computing,School of Microelectronics,Beihang University,Beijing 100191,China;Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Beihang-Goertek Joint Microelectronics Institute,Qingdao Research Institute,Beihang University,Qingdao 266000,China)

机构地区：[1]北京航空航天大学电子信息工程学院,北京100191 [2]北京航空航天大学微电子学院,大数据科学与脑机智能高精尖创新中心,北京100191 [3]中国科学院物理研究所,北京凝聚态物理国家重点实验室,北京100190 [4]中国科学院大学物理学院,北京100049 [5]北京航空航天大学青岛研究所,北航歌尔联合微电子研究所,青岛266000

出　　处：《物理学报》2020年第20期68-75,共8页Acta Physica Sinica

基　　金：北京市自然科学基金(批准号:4194083);国家自然科学基金(批准号:61905007,61774013,11827807,61731001);国家重点研发计划(批准号:2019YFB2203102)资助的课题.

摘　　要：系统研究了退火效应对飞秒激光脉冲驱动的基于钴铁硼/重金属异质结辐射太赫兹波的影响.通过对发射样品进行退火处理,在钨/钴铁硼结构中观察到三倍增强的太赫兹波辐射,而铂/钴铁硼结构中太赫兹波的强度也获得了双倍提升.通过太赫兹时域光谱系统对异质结样品的透射测量和四探针法电阻率测量实验,验证了退火效应的主要机理可能源于材料结晶引起的热电子平均自由程增加,以及材料对太赫兹波的吸收降低.本研究不仅加深了对自旋太赫兹辐射机理的理解,而且为研制高性能太赫兹辐射源及其应用有一定的贡献.We systematically investigate the influence of annealing effect on terahertz(THz)generation from CoFeB/heavy metal heterostructures driven by femtosecond laser pulses.The THz yield is achieved to increase triply in W/CoFeB through annealing effect,and doubly in Pt/CoFeB.The annealing effect originates from both the decrease of synthetic effect of THz absorption and the increase of hot electron mean free path induced by crystallization,with the latter being dominant,which is experimentally corroborated by THz transmission measurement of time-domain spectrum and four-probe resistivity t.Our observations not only deepen understand the spintronic THz radiation mechanism but also provide a novel platform for high speed spintronic opto-electronic devices.

关 键 词：太赫兹产生 铁磁/重金属异质结 退火效应 超扩散模型 

分 类 号：O441.4[理学—电磁学] O482.523[理学—物理]