%0 Journal Article
%T Physical origin of transient Kerr peak induced by circularly polarized laser in ferromagnetic films<br>铁磁薄膜中圆偏振光感应的瞬态磁光Kerr峰的物理起源
%A Chen Da-Xin
%A Chen Zhi-Feng
%A Xu Chu-Dong
%A Lai Tian-Shu
%A <br>陈达鑫
%A 陈志峰
%A 徐初东
%A 赖天树
%J 物理学报
%D 2010
%I 
%X The magnetization dynamics of in-plane anisotropic FePt and perpendicularly anisotropic GdFeCo films induced by circularly polarized laser excitation is investigated using femtosecond time-resolved pump-probe Kerr spectroscopy. It is found that a transient Kerr peak occurs near zero-time delay, respectively for each sample. The origin of the peaks is analyzed. It is pointed out that the transient Kerr peaks are not related to ferromagnetism and may originate from paramagnetic magnetization of free electrons in the samples, while the magnetic field that magnetizes the free electrons comes from inverse Faraday effect of the circularly polarized pump laser. The calculation results based on the paramagnetic magnetization model support such a viewpoint. Based on our points, the duration of magnetic pulses induced by inverse Faraday effect should be the same as that of the pump laser pulses.
%K circularly polarized laser
%K inverse Faraday effect
%K free electrons
%K paramagnetism<br>圆偏振激光
%K 逆Faraday效应
%K 自由电子
%K 顺磁性
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=6E709DC38FA1D09A4B578DD0906875B5B44D4D294832BB8E&cid=47EA7CFDDEBB28E0&jid=29DF2CB55EF687E7EFA80DFD4B978260&aid=99779DD9907819F1E2796CD713FD74F4&yid=140ECF96957D60B2&vid=6AC2A205FBB0EF23&iid=F3090AE9B60B7ED1&sid=F382E03A3BDDFD15&eid=0C24749E1D5BA4C2&journal_id=1000-3290&journal_name=物理学报&referenced_num=1&reference_num=15