A Natural Topological Insulator

Abstract

The earth's crust and outer space are rich sources of technologically relevant materials which have found application in a wide range of fields. Well-established examples are diamond, one of the hardest known materials, or graphite as a suitable precursor of graphene. The ongoing drive to discover novel materials useful for (opto)electronic applications has recently drawn strong attention to topological insulators. Here, we report that Kawazulite, a mineral with the approximate composition Bi${}_2$(Te,Se)${}_2$(Se,S), represents a naturally occurring topological insulator whose electronic properties compete well with those of its synthetic counterparts. Kawazulite flakes with a thickness of a few tens of nanometers were prepared by mechanical exfoliation. They exhibit a low intrinsic bulk doping level and correspondingly a sizable mobility of surface state carriers of more than $1000{\text{cm}}^2/(\text{V s})$ at low temperature. Based on these findings, further minerals which due to their minimized defect densities display even better electronic characteristics may be identified in the future.

References in corpus (7)

• Electric Field Effect in Atomically Thin Carbon Films
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Impurity effect on weak anti-localization in the topological insulator Bi2Te3
• Topological Surface States and Dirac point tuning in ternary Bi2Te2Se class of topological insulators
• Growth of High-Mobility Bi2Te2Se Nanoplatelets on hBN Sheets by van der Waals Epitaxy
• Two-dimensional universal conductance fluctuations and the electron-phonon interaction of topological surface states in Bi2Te2Se nanoribbons
• Two-dimensional magnetotransport in Bi2Te2Se nanoplatelets

Cited by in corpus (17)

• Colloquium: Topological Band Theory
• Control of biaxial strain in single-layer Molybdenite using local thermal expansion of the substrate
• Naturally occurring van der Waals materials
• Tomography of band insulators from quench dynamics
• Quantum Coherent Transport in SnTe Topological Crystalline Insulator Thin Films
• Two-Dimensional Inversion Asymmetric Topological Insulators in Functionalized III-Bi Bilayers
• Tunable interaction-induced localization of surface electrons in antidot nanostructured Bi2Te3 thin films
• Weak Antilocalization and Universal Conductance Fluctuations in Bismuth Telluro-Sulfide Topological Insulators
• Characterizing the weak topological properties: Berry phase point of view
• Indications of the topological transport by the universal conductance fluctuations in the Bi2Te2Se microflakes
• Topological Effects on the Magnetoconductivity in Topological Insulators
• Robust two-dimensional superconductivity and vortex system in Bi2Te3/FeTe heterostructures
• Measuring the topological phase transition via the single-particle density matrix
• Spin-orbit coupling in the kagome lattice with flux and time-reversal symmetry
• Universal Conductance Fluctuations of Topological Insulators
• Floquet topological phases with high Chern numbers in a periodically driven extended Su-Schrieffer-Heeger model
• Influence of Device Geometry on Transport Properties of Topological Insulator Microflakes