Spatial charge inhomogeneity and defect states in topological Dirac semimetal thin films of Na.sub.3./sub.Bi

0511228 - FZÚ 2020 RIV US eng J - Journal Article
Edmonds, M. T. - Collins, J.L. - Hellerstedt, Jack - Yudhistira, I. - Gomes, L.C. - Rodrigues, J.N.B. - Adam, S. - Fuhrer, M.S.
Spatial charge inhomogeneity and defect states in topological Dirac semimetal thin films of Na₃Bi.
Science Advances. Roč. 3, č. 12 (2017), s. 1-7, č. článku eaao6661. ISSN 2375-2548. E-ISSN 2375-2548
Institutional support: RVO:68378271
Keywords : single-electron * topological Dirac semimetals * defect states * scanning tunneling microscope * quantum dot * thin films * spatial charge
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 11.511, year: 2017
Method of publishing: Open access

Topological Dirac semimetals (TDSs) are three-dimensional analogs of graphene, with carriers behaving like massless Dirac fermions in three dimensions. In graphene, substrate disorder drives fluctuations in Fermi energy, necessitating construction of heterostructures of graphene and hexagonal boron nitride (h-BN) to minimize the fluctuations. Three-dimensional TDSs obviate the substrate and should show reduced E F fluctuations due to better metallic screening and higher dielectric constants. We map the potential fluctuations in TDS Na 3 Bi using a scanning tunneling microscope. The rms potential fluctuations are significantly smaller than the thermal energy room temperature and comparable to the highest- quality graphene on h-BN. Surface Na vacancies produce a novel resonance close to the Dirac point with surprisingly large spatial extent and provide a unique way to tune the surface density of states in a TDS thin-film material.

Permanent Link: http://hdl.handle.net/11104/0301550