Electron correlation in FeTe studied by photoemission spectroscopy
L. C. C. Ambolode II 1 , H. Suzuki 1 , S. Ideta 1 , T. Yoshida1,3 ,
A. Fujimori 1,3 , K. Ono 2 , H. Kumigashira 2 , L. Liu 1 ,
M. Takahashi 1 , T. Kakeshita 1,3 , S. Uchida 1,3
1
Department of Physics, University of Tokyo, Tokyo 113-0033 , Japan
2
Photon Factory, IMSS, KEK, Ibaraki 305-0801, Japan
3
JST, TRIP, Tokyo 102-0075, Japan
Electron correlation effects in iron-based
superconductors
investigated
(FeSCs)
extensively
in
have
a
been
number
theoretical and experimental studies
of
[1-2].
Among the FeSCs, FeTe compound was found
to have a relatively high electron correlation. In
this study, resonant photoemission experiment
was performed on as-grown FeTe samples in
order to examine the electron correlation effects
on its electronic structure.
Valence-band photoemission spectra of FeTe
taken at various photon energies are shown in
Fig. 1(a). It can be seen that the intensity of the
-0.5 eV structure as well as the -2.5 eV shoulder
exhibit strong photon energy dependence. The
photon energy-dependence of the intensity in
Fig. 1(b) imply that Fe 3p→3d resonance occurs
around hv ~ 55 eV and that near-E F states down
Fig. 1. Valence-band photoemission
spectra of FeTe. (a) Photoemission
spectra for various photon energies.
(b) Plot of photoemission intensities
at E = -0.2, -0.5 and -2.5 eV as
functions of photon energy. (c) Fe 3d
partial density of states of FeTe. (d)
Comparison with the FeTe total DOS
band calculation [3].
to ~-2.5 eV are mainly Fe 3d states. The broad feature which is shifted towards
higher binding energy as the photon energy increases,
marked by vertical bars
in Fig. 1(a), is due to Auger-electron emission [4].
[1] A. Tamai, et al., Phys. Rev. Lett. 104, 097002 (2010).
[2] Z. P. Yin et al., Nature Materials 10, 932 (2011).
[3] T. Miyake et al, J. Phys. Soc. Jpn. 79, 044705 (2010).
[4] W. Malaeb et al., J. Phys. Soc. Jpn. 77, 093714 (2008).