Ultrafast Modulation of the Chemical Potential in BaFe2As2 by Coherent Phonons
Ultrafast Modulation of the Chemical Potential in BaFe2As2 by Coherent Phonons
复制标题
相干声子对 BaFe2As2 化学势的超快调制
DOI：
10.1103/physrevlett.112.207001
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发表时间：
2014-05-21
影响因子：
8.6
通讯作者：
Rossnagel, K.
中科院分区：
文献类型：
--
作者：
Yang, L. X.;Rohde, G.;Rossnagel, K.
作者：杨LX;罗德，G；罗威尔，T；斯坦奇，A；汉夫，K；索特，C；雷蒂格，L；科尔特斯，R；陈F；冯德龙;沃尔夫，T；坎布尔，B；埃雷明，我；波明切夫，T；默南，MM；卡普坦，HC；基普，L；芬克，J；鲍尔，M；博文西彭，U；罗斯纳格尔，K |摘要: 利用时间和角度分辨极紫外光电子能谱研究了 BaFe2As2 高对称点 Γ 和 M 附近的电子结构动力学，观察到费米能级在 A1g(As) 声子模式频率下的全局振荡。有人认为，这种行为反映了光激发表面区域有效化学势的调制，这种调制是由于费米能级附近的能带结构对 A1g(As) 声子模式的高敏感性以及垂直于层的低电子扩散率而产生的。结果建立了一种调节铁磷化物电子特性的新方法：有效化学势的相干控制。结果进一步表明，在弱层间耦合材料的超快电子结构动力学中，需要考虑有效化学势的平衡时间。 © 2014 美国物理学会。
Author(s): Yang, LX; Rohde, G; Rohwer, T; Stange, A; Hanff, K; Sohrt, C; Rettig, L; Cortes, R; Chen, F; Feng, DL; Wolf, T; Kamble, B; Eremin, I; Popmintchev, T; Murnane, MM; Kapteyn, HC; Kipp, L; Fink, J; Bauer, M; Bovensiepen, U; Rossnagel, K | Abstract: Time- and angle-resolved extreme ultraviolet photoemission spectroscopy is used to study the electronic structure dynamics in BaFe2As2 around the high-symmetry points Γ and M. A global oscillation of the Fermi level at the frequency of the A1g(As) phonon mode is observed. It is argued that this behavior reflects a modulation of the effective chemical potential in the photoexcited surface region that arises from the high sensitivity of the band structure near the Fermi level to the A1g(As) phonon mode combined with a low electron diffusivity perpendicular to the layers. The results establish a novel way to tune the electronic properties of iron pnictides: coherent control of the effective chemical potential. The results further suggest that the equilibration time for the effective chemical potential needs to be considered in the ultrafast electronic structure dynamics of materials with weak interlayer coupling. © 2014 American Physical Society.