Graduate School of Advanced Science and Engineering, Hiroshima University International Institute for Sustainability with Knotted Chiral Meta Matter (SKCM2), Hiroshima University, Japan Research Institute for Semiconductor Engineering, Hiroshima University Hiroshima Synchrotron Radiation Center (HiSOR), Hiroshima University
03.06.2024. u 11:00h
Institute of Physics, 1st wing lecture room & Zoom
Solids with competing interactions often undergo complex phase transitions with a variety of long periodic modulations. Among such transition, devil’s staircase is one of the most complex phenomenon, and for it, CeSb is the most famous material, where a number of the distinct phases with long-periodic antiferromagnetostructures sequentially appear below the Néel temperature [1]. An evolution of the low energy electronic structures and underlying electronic correlations going through the devil’s staircase is of special interest to understand its mechanism, which has, however, been elusive despite 40 years of intense research.
In my presentation, I will introduce our recent investigations of the electronic properties undergoing the devil’s staircase by using laser-based angle-resolved photoemission spectroscopy. We reveal the paramagnetic electronic structure with the semimetal feature [2]. The high-energy resolution and bulk-sensitivity achieved by utilizing low-energy laser source reveals the significant reconstruction of these itinerant bands and the many-body interactions, which have so far evaded from the experimental detection. The reconstruction of itinerant bands to the 4f order is dramatically changed at each distinct transition of the devil’s staircase, and it exposes the strong electronic anisotropy across TN [3]. Moreover, we discovered a new type of electron-boson coupling between the mobile electrons and crystal-electric-field excitations of the 4f-orbitals, which renormalizes the Sb 5p band prominently, yielding a remarkable kink at very low energy. This coupling strength of the many body state is exceedingly strong and anomalously enhanced during the devil’s staircase transition [4].
References
[1] J. Rossat-Mignod et al.,J. Magn. Magn. Mater. 52, 111 (1985).
[2] K. Kuroda et al., Physical Review Letters 120, 086402 (2018).
[3] K. Kuroda et al., Nature Communications 11, 2888 (2020).
[4] Y. Arai, K. Kuroda et al., Nature Materials 21, 410 (2022).
Join Zoom Meeting:
https://us06web.zoom.us/j/5081440931
Meeting ID: 508 144 0931
Seminar hosts: Neven Šantić i Matija Čulo