Observation of longitudinal magnetic fluctuations at a first-order ferromagnetic quantum phase transition in UGe

Noma, Yuichiro*; Kotegawa, Hisashi*; Kubo, Tetsuro*; To, Hideki*; Harima, Hisatomo*; Haga, Yoshinori; Yamamoto, Etsuji; Onuki, Yoshichika*; Ito, Kohei*; Nakamura, Ai*; et al.

Journal of the Physical Society of Japan, 90(7), p.073707_1 - 073707_5, 2021/07

https://doi.org/10.7566/JPSJ.90.073707

Emergent Weyl fermion excitations in TaP explored by Ta quadrupole resonance

Yasuoka, Hiroshi; Kubo, Tetsuro*; Kishimoto, Yasuki*; Kasinathan, D.*; Schmidt, M.*; Yan, B.*; Zhang, Y.*; To, Hideki*; Felser, C.*; Mackenzie, A. P.*; et al.

Physical Review Letters, 118(23), p.236403_1 - 236403_6, 2017/07

https://doi.org/10.1103/PhysRevLett.118.236403

The Ta quadrupole resonance (NQR) technique has been utilized to investigate the microscopic magnetic properties of the Weyl semi-metal TaP. We found three zero-field NQR signals associated with the transition between the quadrupole split levels for Ta with =7/2 nuclear spin. A quadrupole coupling constant, = 19.250 MHz, and an asymmetric parameter of the electric field gradient, = 0.423 were extracted, in good agreement with the theoretical calculations. In order to examine the magnetic excitations, the temperature dependence of the spin lattice relaxation rate (1/) has been measured for the -line ( transition). We found that there exist two regimes with quite different relaxation processes. Above *K, a pronounced ( behavior was found which is attributed to the magnetic excitations at the Weyl nodes with temperature dependent orbital hyperfine coupling. Below *, the relaxation is mainly governed by Korringa process with (1/) = constant, while we have to include a type dependence in order to reproduce our experimental data. We show that Ta-NQR is a novel probe for the bulk Weyl fermions and their excitations.

Development of JAERI-tandem superconducting booster

; Ishii, Tetsuro; Ikezoe, Hiroshi; Okubo, Makio

Proceedings of 12th Linear Accelerator Meeting in Japan, p.36 - 38, 1987/00

no abstracts in English