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arXiv · 1809.06998

ARPES/STM study of the surface terminations and 5$f$-electron character in URu$_2$Si$_2$

W. Zhang·H. Y. Lu·D. H. Xie·W. Feng·S. Y. Tan·Y. Liu·X. G. Zhu·Y. Zhang·Q. Q. Hao·Y. B. Huang·X. C. Lai·Q. Y. Chen
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Abstract

Hidden order in URu$_2$Si$_2$ has remained a mystery now entering its 4th decade. The importance of resolving the nature of the hidden order has stimulated extensive research. Here we present a detailed characterization of different surface terminations in URu$_2$Si$_2$ by angle-resolved photoemission spectroscopy, in conjunction with scanning tunneling spectroscopy and DMFT calculations that may unveil a new piece of this puzzle. The U-terminated surface is characterized by an electron-like band around the $\bar{X}$ point, while a hole-like band for the Si-terminated surface. We also investigate temperature evolution of the electronic structure around the $\bar{X}$ point from 11 K up to 70 K, and did not observe any abrupt change of the electronic structure around the coherence temperature (55 K). The $f$ spectral weight gradually weakens upon increasing temperature, still some $f$ spectral weight can be found above this temperature. Our results suggest that surface terminations in URu$_2$Si$_2$ are an important issue to be taken into account in future work.

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W. Zhang, H. Y. Lu, D. H. Xie, W. Feng, S. Y. Tan, Y. Liu, X. G. Zhu, Y. Zhang, Q. Q. Hao, Y. B. Huang, X. C. Lai, Q. Y. Chen. 2018-09-19. ARPES/STM study of the surface terminations and 5$f$-electron character in URu$_2$Si$_2$. https://doi.org/10.1103/physrevb.98.115121

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