量子物質科學協同創新中心 & 物理系學術報告： STM & ARPES studies on Metal-oxides & -chalcogenides films

報告題目： STM & ARPES studies on Metal-oxides & -chalcogenides films 報告人： Young Jun Chang Department of Physics, University of Seoul, Seoul, Republic of Korea 報告時間： 2016-12-2 11:00 報告地點：物理系理科樓B406 主辦單位：物理系摘要： Two-dimensional (2D) systems, such as graphene, transition metal chalcogenide (TMC), and transition metal oxide (TMO) hetero-interfaces, display very intriguing properties, which are not shown in their bulk form. 2D confinement significantly alters electronic wave function on top of electronic correlations with lattice, spin, and orbital. We have studied near-surface electronic properties on TMO and TMC by using in situ STM & ARPES. On PLD-grown TMO films, we have studied growth dynamics in the ultrathin SrTiO3 and SrRuO3 [1] and newly appeared 2D states in the hetero-interfaces (LaTiO3/SrTiO3,[2] and LaNiO3/SrTiO3[3]). On MBE-grown TMC films, we also performed ex situ ARPES studies by using Se capping method. We examined high temperature stability of few layer thick MoSe2 films by using ellipsometry. We discuss our ARPES data on other TMC films on graphene/SiC substrates. [Acknowledgement: NRF-2014R1A1A1002868]
[1] ACS Nano 10, 5383 (2016), 'Direct Nanoscale Analysis of Temperature-Resolved Growth Behaviors of Ultrathin Perovskites on SrTiO3', YJC, S.-H. Phark
[2] Phys. Rev. Lett. 111, 126401 (2013), ‘Layer-by-layer evolution of a two-dimensional electron gas near an oxide interface’, YJC, et al.
[3] Scientific Reports 5, 8746 (2015), 'Latent instabilities in metallic LaNiO3 films by strain control of Fermi-surface topology', H. K. Yoo, H. D. Kim*, YJC*, et al.