2017/11/20 by Ye-Heng Song, Zhen-Yu Jia, Dongqin Zhang +9 · 3 citations
Materials Science · Physics and Astronomy · #2D Materials and Applications #Band gap #Coulomb #Coupling (piping) #Gapless playback #Graphene research and applications #Quantum Hall effect #Quantum spin Hall effect #Quantum tunnelling #Quasiparticle #Spin (aerodynamics) #Topological Materials and Phenomena #Topological insulator #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1038/s41467-018-06635-x
13 pages, 4 figures
arxiv created 2017/11/20 · openalex created_date 2017/12/04 · openalex publication_date 2018/09/28 · arxiv updated 2018/10/24 · openalex updated_date 2026/08/05
Abstract The two-dimensional topological insulators host a full gap in the bulk band, induced by spin–orbit coupling (SOC) effect, together with the topologically protected gapless edge states. However, it is usually challenging to suppress the bulk conductance and thus to realize the quantum spin Hall (QSH) effect. In this study, we find a mechanism to effectively suppress the bulk conductance. By using the quasiparticle interference technique with scanning tunneling spectroscopy, we demonstrate that the QSH candidate single-layer 1 T ’-WTe 2 has a semimetal bulk band structure with no full SOC-induced gap. Surprisingly, in this two-dimensional system, we find the electron–electron interactions open a Coulomb gap which is always pinned at the Fermi energy ( E F ). The opening of the Coulomb gap can efficiently diminish the bulk state at the E F and supports the observation of the quantized conduction of topological edge states.