Symmetry breaking in iron chalcogenides and kagome metal systems probed by electronic Raman spectroscopy

by Dr Shangfei Wu (Beijing Academy of Quantum Information Sciences)

Wednesday 1 Nov 2023, 10:00 → 11:00 Asia/Shanghai

TDLI Meeting Room N601 (East Wing of Floor 6, North Building)

Abstract

Raman scattering is an inelastic light scattering process capable of probing the lattice, charge, orbital, and spin degrees of freedom in crystals, enabling the detection of excitations with controlled symmetry defined by the incident and scattered light polarizations. The temperature evolution of these excitations across phase transitions provides an unambiguous identification of the underlying broken symmetries and the emergent collective modes. In this talk, I will first briefly introduce the electronic Raman spectroscopy. In the second part, I will illustrate how this technique is used to probe the nematic fluctuations and Fermi liquid to non-Fermi liquid crossover in the FeSe1-xSx system [1]. In the third part, I will show our recent new results of the symmetry breaking and ascending phenomena in the charge density wave state of the kagome metal systems, including the interplay between multicomponent charge density wave orders in kagome superconductor AV3Sb5 [2] and the three-fold symmetry breaking in the magnetic kagome FeGe system [3].

[1] W.-L. Zhang, S.-F. Wu et al PNAS 118 (20) e2020585118 (2021)
[2] S.-F. Wu et al, Phys. Rev. B 105,155106 (2022) Editors’ Suggestion
[3] S.-F. Wu et al arXiv: 2309.14314

Biography

Shangfei Wu received his Ph.D. in physics from the Institute of Physics, Chinese Academy of Sciences in 2018 under the supervision of Prof. Pierre Richard and Prof. Hong Ding. After that, he did his postdoctoral research at the National Laboratory for Intense Magnetic Fields in Grenoble, France from the year of 2018 to 2019. He then moved to the Department of Physics & Astronomy, Rutgers, The State University of New Jersey under the supervision of Prof. Girsh Blumberg from 2019 to 2023. In August 2023, He joined the Beijing Academy of Quantum Information Sciences as an associate researcher. His research interests focus on the electronic Raman spectroscopic study of strongly correlated electron systems, such as iron-based superconductors and kagome metal systems.

Division

Condensed Matter

Other information

Tencent meeting link: https://meeting.tencent.com/dm/KEBLKsGWv5Dn   Meeting ID: 299 980 164