Observation of Coulomb gap in the quantum spin Hall candidate single-layer 1T’-WTe2

• DOI: 10.1038/s41467-018-06635-x
• Publication Date: 2018-09-28T10:26:51Z
• Authors: Ye-Heng Song; Zhen-Yu Jia; Dongqin Zhang; Xin-Yang Zhu; Zhi-Qiang Shi; Huaiqiang Wang; Li Zhu; Qian-Qian Yuan; Haijun Zhang; Ding-Yu Xing; Shao-Chun Li
• Keywords: Condensed Matter - Materials Science; Condensed Matter - Mesoscale and Nanoscale Physics; Science; Q; Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences; 01 natural sciences; Article; Mesoscale and Nanoscale Physics (cond-mat.mes-hall); 0103 physical sciences

Abstract The two-dimensional topological insulators host a full gap in the bulk band, induced by spin–orbit coupling (SOC) effect, together with topologically protected gapless edge states. However, it is usually challenging to suppress conductance and thus realize quantum spin Hall (QSH) effect. In this study, we find mechanism effectively conductance. By using quasiparticle interference technique scanning tunneling spectroscopy, demonstrate that QSH candidate single-layer 1 T ’-WTe 2 has semimetal band structure no SOC-induced gap. Surprisingly, system, electron–electron interactions open Coulomb which always pinned at Fermi energy ( E F ). opening of can efficiently diminish state supports observation quantized conduction