JPS Conf. Proc. 30, 011120 (2020) [6 pages]
Proceedings of the International Conference on Strongly Correlated Electron Systems (SCES2019)
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Optical Conductivity Study of f Electron States in YbCu2Ge2 at High Pressures to 20 GPa
Hidekazu Okamura1,*, Makoto Nagata2, Atsushi Tsubouchi1, Yoshichika Ōnuki3, Yuka Ikemoto4, and Taro Moriwaki4
1Graduate School of Advanced Technology and Science, Tokushima University, Tokushima 770-8506, Japan
2Graduate School of Science, Kobe University, Kobe 657-8501, Japan
3Faculty of Science, University of the Ryukyus, Okinawa 903-0213, Japan
4Japan Synchrotron Radiation Research Center, Sayo, Hyogo 679-5198, Japan
Graduate School of Natural Science and Technology, Shimane University, Matsue 690-8504, Japan
Received September 10, 2019

Optical conductivity [\(\sigma (\omega )\)] of YbCu2Ge2 has been measured at external pressures (P) to 20 GPa, to study the P evolution of f electron hybridized states. At P = 0, \(\sigma (\omega )\) shows a marked mid-infrared (mIR) peak at 0.37 eV, which is due to optical excitations from f14 (Yb2+) state located below the Fermi level. With increasing P, the mIR peak shows significant shifts to lower energy, reaching 0.18 eV at P = 20 GPa. This result indicates that the f14 energy level increases toward the Fermi level with P. Such a shift of the f electron level with P has been expected from theoretical considerations, but had never been demonstrated by spectroscopic experiment under high P. The obtained results are also analyzed in terms of the P evolution of the conduction-f electron hybridization.

©2020 The Author(s)
This article is published by the Physical Society of Japan under the terms of the Creative Commons Attribution 4.0 License. Any further distribution of this work must maintain attribution to the author(s) and the title of the article, journal citation, and DOI.
https://doi.org/10.7566/JPSCP.30.011120

References

  • 1) N. D.Dung, T. D.Matsuda, Y.Haga, S.Ikeda, E.Yamamoto, T.Ishikura, T.Endo, S.Tatsuoka, Y.Aoki, H.Sato, T.Takeuchi, R.Settai, H.Harima, and Y.Ōnuki, J. Phys. Soc. Jpn. 78, 084711 (2009). 10.1143/JPSJ.78.084711[Abstract] Google Scholar
  • 2) A.Miyake, F.Honda, T.Watanuki, A.Machida, D.Kawana, K.Shimizu, R.Settai, and Y.Ōnuki, unpublished data.Google Scholar
  • 3) A.Miyake, F.Honda, R.Settai, K.Shimizu, and Y.Ōnuki, J. Phys. Soc. Jpn. 81, SB054 (2012). 10.1143/JPSJS.81SB.SB054[Abstract] Google Scholar
  • 4) A.Yasui, S.-I.Fujimori, I.Kawasaki, T.Okane, Y.Takeda, Y.Saitoh, H.Yamagami, A.Sekiyama, R.Settai, T. D.Matsuda, Y.Haga, and Y.Ōnuki, J. Phys.: Conf. Ser. 273, 012067 (2011). 10.1088/1742-6596/273/1/012067 Google Scholar
  • 5) For a recent review, see, for example, R. Y.Chen and N. L.Wang, Rep. Prog. Phys. 79, 064502 (2016), and the references cited therein. 10.1088/0034-4885/79/6/064502 Google Scholar
  • 6) H.Okamura, T.Watanabe, M.Matsunami, T.Nishihara, N.Tsujii, T.Ebihara, H.Sugawara, H.Sato, Y.Ōnuki, Y.Ishikawa, T.Takabatake, and T.Nanba, J. Phys. Soc. Jpn. 76, 023703 (2007). 10.1143/JPSJ.76.023703[Abstract] Google Scholar
  • 7) H.Okamura, Y.Ikemoto, T.Moriwaki, and T.Nanba, Jpn. J. Appl. Phys. 56, 05FA11 (2017). 10.7567/JJAP.56.05FA11 Google Scholar
  • 8) S.Kimura and H.Okamura, J. Phys. Soc. Jpn. 82, 021004 (2013). 10.7566/JPSJ.82.021004[Abstract] Google Scholar
  • 9) Y.Ikemoto, T.Moriwaki, T.Hirono, S.Kimura, K.Shinoda, M.Matsunami, N.Nagai, T.Nanba, K.Kobayashi, and H.Kimura, Infrared Phys. Technol. 45, 369 (2004). 10.1016/j.infrared.2004.01.004 Google Scholar
  • 10) T.Moriwaki and Y.Ikemoto, Infrared Phys. Technol. 51, 400 (2008). 10.1016/j.infrared.2007.12.031 Google Scholar
  • 11) M.Dressel and G.Grüner, Electrodynamics of Solids (Cambridge University Press, Cambridge, U.K., 2002). Google Scholar
  • 12) H.Okamura, J. Phys.: Conf. Ser. 359, 012013 (2012). 10.1088/1742-6596/359/1/012013 Google Scholar
  • 13) D. L.Cox, Phys. Rev. Lett. 58, 2730 (1987). 10.1103/PhysRevLett.58.2730 Google Scholar
  • 14) P.Coleman, arXiv:1509.05769.Google Scholar
  • 15) K.Nishiyama, T.Mito, G.Pristas, T.Koyama, K.Ueda, T.Kohara, S.Gabani, K.Flachbart, H.Fukazawa, Y.Kohori, N.Takeshita, N.Shitsevalova, and H.Ikeda, Phys. Rev. B 93, 121111(R) (2016). 10.1103/PhysRevB.93.121111 Google Scholar
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