セミナー案内

日時
5月 14日 (水), 13:30-
場所
Onsite style (Room 413)
お問い合わせの際はtanaka.hiroto.54z[@]st.kyoto-u.ac.jp ([]を外す) までご連絡ください。
講演者
Dr. Makoto Shimizu (Condensed Matter Theory Group)
タイトル
"Electronic and Magnetic Structures of UTe2"
備考欄　（アブストラクト等）

Abstract:
 The heavy-fermion paramagnetic superconductor UTe2 has been extensively studied as a strong candidate for spin-triplet superconductivity. Early studies suggested the presence of ferromagnetic fluctuations, which were considered a potential pairing mechanism for spin-triplet Cooper pairs. However, neutron scattering experiments have revealed antiferromagnetic fluctuations instead. Some theoretical works propose that spin-triplet pairing may be mediated by these antiferromagnetic fluctuations. Nevertheless, more realistic models incorporating sublattice, orbital, and spin degrees of freedom are required to fully understand the magnetic structure and pairing mechanism.
 In this study, we investigate the electronic and magnetic structures of UTe2. We begin with first-principles calculations based on density functional theory (DFT) including spin-orbit coupling. Using symmetry-conserving projected Wannier functions, we construct a 72-band tight-binding model comprising U 5f, U 6d, and Te 5p orbitals. At the Fermi level, the U 5f (j = 5/2) orbitals dominate the density of states. Focusing on these orbitals, we calculate the irreducible susceptibility. In this seminar, I will present the calculated spin susceptibility and discuss its comparison with experimental results.

References:
[1] D. Braithwaite et al., Commun. Phys. 2, 1 (2019).
[2] S. M. Thomas et al., Sci. Adv. 6, eabc8709 (2020).
[3] D. Aoki et al., J. Phys. Soc. Jpn. 89, 053705 (2020).
[4] S. Ran et al., Phys. Rev. B 101, 140503 (2020).
[5] W. Knafo et al., arXiv:2311.05455.
[6] M. Shimizu, and Y. Yanase, arXiv:2408.04292.