Ultrafast Electron Dynamics in Epitaxial Graphene Investigated with Time- and Angle-Resolved Photoemission Spectroscopy
Søren Ulstrup, Jens Christian Johannsen, Alberto Crepaldi, Federico Cilento, Michele Zacchigna, Cephise Cacho, Richard T. Chapman, Emma Springate, Felix Fromm, … 展开作者
Søren Ulstrup, Jens Christian Johannsen, Alberto Crepaldi, Federico Cilento, Michele Zacchigna, Cephise Cacho, Richard T. Chapman, Emma Springate, Felix Fromm, Christian Raidel, Thomas Seyller, Fulvio Parmigiani, Marco Grioni, Philip Hofmann
备注：
8 pages, 6 figures
发表信息：
Journal of Physics: Condensed Matter, 27, 164206 (2015)
In order to exploit the intriguing optical properties of graphene it is essential to gain a better understanding of the light-matter interaction in the material on ultrashort timescales. Exciting the Dirac fermions with intense ultrafast laser pulses triggers a series of processes involving interactions between electrons, phonons and impurities. Here we study these interactions in epitaxial graphene supported on silicon carbide (semiconducting) and iridium (metallic) substrates using ultrafast time- and angle-resolved photoemission spectroscopy (TR-ARPES) based on high harmonic generation. For the semiconducting substrate we reveal a complex hot carrier dynamics that manifests itself in an elevated electronic temperature and an increase in linewidth of the $π$ band. By analyzing these effects we are able to disentangle electron relaxation channels in graphene. On the metal substrate this hot carrier dynamics is found to be severely perturbed by the presence of the metal, and we find that the electronic system is much harder to heat up than on the semiconductor due to screening of the laser field by the metal.
Hole-doping-induced changes in the electronic structure of La$_{1-x}$Sr$_x$FeO$_3$ : soft x-ray photoemission and absorption study of epitaxial thin films
Signatures of superconductivity and pseudogap formation in non-equilibrium nodal quasiparticles revealed by ultrafast angle-resolved photoemission
我们用时间分辨和角分辨光电子能谱测量了$_2$ $_2$ O $_2$的各种掺杂的节非平衡电子态。我们发现，这些ungapped状态的初始泵浦诱导的瞬态信号的强烈影响的超导能隙在$T_c$，超导配对波动在$T_p$，和赝能隙在$T^*$的发病。此外，$T_p$标记了通量依赖性瞬态信号中的一个提示性阈值，出现了低于$T_p$的临界通量，该临界通量对应于使所有库珀对断裂所需的能量。这些结果挑战了铜氧化物超导体中结-反结二分法的概念，在结准粒子和铜氧化物相图之间建立了一个新的联系。
Time-Resolved Photoemission Spectroscopy of Quantum Materials Using High Harmonic Generation: Probing Electron-Phonon Interactions and Non-Equilibrium Dynamics
Anomalous contribution to the nematic electronic states from the structural transition in FeSe revealed by time- and angle-resolved photoemission spectroscopy
Excited state band mapping and momentum-resolved ultrafast population dynamics in In/Si(111) nanowires investigated with XUV based time- and angle-resolved photoemission spectroscopy
Clustering-Enhanced Time- and Angle-Resolved Photoemission Study of LaTe$_3$: Absence of a Photoinduced Secondary CDW in the Electronic Structure
Aarhus University（奥胡斯大学）；CNR, Consiglio Nazionale delle Ricerche, Istituto officina dei materiali（意大利国家研究委员会材料研究所）；Central Laser Facility, STFC Rutherford Appleton Laboratory（STFC鲁瑟福阿普尔顿实验室中央激光设施）；SUPA, School of Physics and Astronomy, University of St Andrews（圣安德鲁斯大学物理与天文学学院）；Stanford University（斯坦福大学）；Diamond Light Source Ltd（钻石光源有限公司）；Princeton University（普林斯顿大学）；Department of Physics, Indian Institute of Technology Guwahati（印度理工学院古瓦哈提分校物理系）
Ultrafast recovery dynamics of dimer stripes in IrTe2
University of Fribourg（弗里堡大学）；Fribourg Centre for Nanomaterials（弗里堡纳米材料中心）；Université de Lorraine（洛林大学）；CNRS（法国国家科学研究中心）；IJL（约尔研究所）；Deutsches Elektronen-Synchrotron DESY（德国电子同步辐射研究所）；European XFEL（欧洲XFEL）；Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel（基尔大学实验与应用物理研究所）；Max Planck Institute for Chemical Physics of Solids（马克斯·普朗克固体化学物理研究所）；Ruprecht Haensel Laboratory（鲁普雷希特·亨塞尔实验室）；Department of Quantum Matter Physics, University of Geneva（日内瓦大学量子物质物理系）
Momentum-Selective Electron and Spin Dynamics under Ultrafast Photoexcitation
CPHT, CNRS, École polytechnique, Institut Polytechnique de Paris（法国高等理工学院）；Institut für Theoretische Physik, Universität Hamburg（汉堡大学理论物理研究所）；European X-Ray Free-Electron Laser Facility（欧洲X射线自由电子激光设施）；The Hamburg Centre for Ultrafast Imaging（汉堡超快成像中心）；Collège de France（法兰西学院）
