Probing phonons at FeSe/SrTiO3 interfaces by monochromted STEM-EELS

ORAL

Abstract

Monolayer FeSe films grown on SrTiO3 substrate show over ten-fold increase in superconducting Tc compared to bulk FeSe. The interfacial electron-phonon coupling has been thought as one key factor for the Tc enhancement. So far, the main experimental evidence for electron-phonon coupling is the ~100 meV replica bands observed in angle resolved photoemission spectroscopy. In order to provide an atomic scale understanding of the electron-phonon interaction, here we study the phonons at FeSe/SrTiO3 interface by Å-sized electron beam. We study FeSe/SrTiO3 samples by high resolution electron energy loss spectroscopy in a monochromated scanning transmission electron microscope. We will present atomically resolved phonon spectral images of the FeSe/SrTiO3 interface. Together with the interface atomic structure and chemistry, we will also discuss possible origin of the phonon modes with strong EPC.

* This work was supported by the Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering (DE-SC0014430). The authors acknowledge the use of facilities and instrumentation at the UC Irvine Materials Research Institute (IMRI) supported in part by the National Science Foundation through the Materials Research Science and Engineering Center program (DMR-2011967).

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Presenters

  • Hongbin Yang

    University of California, Irvine

Authors

  • Hongbin Yang

    University of California, Irvine

  • Yinong Zhou

    University of California, Irvine

  • Guangyao Miao

    Chinese Academy of Sciences

  • Xiaofeng Xu

    Chinese Academy of Sciences

  • Xianghan Xu

    Princeton University

  • Xuetao Zhu

    Chinese Academy of Sciences

  • Jiandong Guo

    Chinese Academy of Sciences

  • Ruqian Wu

    University of California, Irvine

  • Xiaoqing Pan

    University of California, Irvine