Chiral charge density waves induced by Ti-doping in 1T-TaS2.

Authors :: Gao, J. J.
Zhang, W. H.
Si, J. G.
Luo, X.
Yan, J.
Jiang, Z. Z.
Wang, W.
Lv, H. Y.
Tong, P.
Song, W. H.
Zhu, X. B.
Lu, W. J.
Yin, Y.
Sun, Y. P.
Source :: Applied Physics Letters; 6/7/2021, Vol. 118 Issue 21, p1-4, 4p
Publication Year :: 2021
Abstract: We investigate the Ti-doping effect on the charge density wave (CDW) of 1T-TaS<subscript>2</subscript> by combining scanning tunneling microscopy measurements and first-principle calculations. Although the Ti-doping induced phase evolution seems regular with an increase of the doping concentration (x), an unexpected chiral CDW phase is observed in the sample with x = 0.08, in which Ti atoms almost fully occupy the central Ta atoms in the CDW clusters. The emergence of the chiral CDW is proposed to be from the doping-enhanced orbital order. Only when x = 0.08, the possible long-range orbital order can trigger the chiral CDW phase. Compared with other 3d-elements doped 1T-TaS<subscript>2</subscript>, the Ti-doping retains the electronic flatband and the corresponding CDW phase, which is a prerequisite for the emergence of chirality. We expect that introducing elements with a strong orbital character may induce a chiral charge order in a broad class of CDW systems. The present results open up another avenue for further exploring the chiral CDW materials. [ABSTRACT FROM AUTHOR]