Peculiar electronic states in IrTe₂ probed by synchrotron radiation spectroscopy

日時　2022年7月26日　（火）　16：20～17：50
場所　広島大学放射光科学研究センター　2階　セミナー室(オンライン併用)
講師　Takashi Mizokawa
(Department of Applied Physics, Waseda University)

One of the layered transition-metal dichalcogenides, IrTe₂, exhibits a structural phase transition from trigonal to monoclinic or triclinic at about 280 K [1]. The lattice distortion of the Ir triangular lattice and the Ir-Ir dimerization can be understood based on the orbitally induced Peierls mechanism [2] as supported by the photoemission studies on IrTe₂ [3,4]. There is an interesting interplay between the structural phase transition and the superconductivity [5,6] in which the multi-band Fermi surfaces are expected to play a significant role. Very recently, IrTe₂ has been attracting revived interest due to its unique domain texture and its peculiar surface states. The quasi 1D surface states were discovered by Ootsuki et al. by means of angle-resolved photoemission spectroscopy (ARPES) at BL-9A, HiSOR [7]. In this seminar, we will discuss spin polarization of the surface states, which is induced by strong Ir 5d/Te 5p spin-orbit interaction, on the basis of spin-resolved ARPES results obtained at BL-9B, HiSOR [8]. In addition, we will discuss the interesting evolution of the domain texture and the domain dependent surface states which have been observed by nano-ARPES at SPECTROMICROSCOPY-3.2L beamline of Elettra.

[1] S. Jobic et al., Z. Anorg. Allg. Chem. 598, 199 (1991).
[2] D. I. Khomskii and T. Mizokawa, Phys. Rev. Lett. 94, 156402 (2005).
[3] D. Ootsuki et al., Phys. Rev. B 86, 014519 (2012).
[4] D. Ootsuki et al., J. Phys. Chem. Solids 128, 270 (2019).
[5] S. Pyon, K. Kudo, and M. Nohara, J. Phys. Soc. Jpn. 81, 053701 (2012).
[6] J. J. Yang et al., Phys. Rev. Lett. 108, 116402 (2012).
[7] D. Ootsuki et al., J. Phys. Soc. Jpn. 86, 123704 (2017).
[8] T. Mizokawa et al. Adv. Quantum Technol. in press (https://doi.org/10.1002/qute.202200029)

問合せ先　出田真一郎、島田賢也（放射光科学研究センター）