|일시||Jan. 11th(Tue), 15:00|
“Ultrafast optical studies on CDW collective modes of the Weyl-CDW (TaSe4)2I”
Department of Physics,
Univ. Illinois at Urbana-Champaign (UIUC)
Jan. 11th (Tue), 15:00, E6 #1501
(TaSe4)2I provides an excellent platform to explore topology, lattice, and charge degrees of freedom. It is a non-magnetic Weyl semimetal with a quasi-1D charge-density wave phase transition (TC ~ 260 K) on its structurally chiral lattice. Because the pairs of Weyl fermions are coupled by a CDW modulation, the phase part of the CDW collective mode is suggested to follow the axion electrodynamics described by θE·B [1,2]. As a result, exciting phenomena such as negative magnetoresistance, quantized photogalvanic and piezomagnetic effects have been proposed [1,3,4]. In this talk, we will investigate the CDW collective modes of (TaSe4)2I using ultrafast optical tools of THz emission and THz-pump birefringence spectroscopy. The experimental results will be discussed and compared to the theoretically suggested magnetoelectric effects in the Weyl-CDW system.
 J. Gooth et al., Nature 575, 315 (2019).
 W. Shi et al., Nat. Phys. 17, 381 (2021).
 D. M. Nenno et al., Nat. Rev. Phys. 2, 682 (2020).
 Yu et al., Phys. Rev. B 104, 174406 (2021).
Contact: Eunjung Jo, (email@example.com)