Related Experiment Video
Updated: Jan 29, 2026

Probing the Structure and Dynamics of Interfacial Water with Scanning Tunneling Microscopy and Spectroscopy
Published on: May 27, 2018
Nonlayered tellurene as an elemental 2D topological insulator: experimental evidence from scanning tunneling
Salma Khatun1, Arnab Banerjee, Amlan J Pal
1School of Physical Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India. sspajp@iacs.res.in.
Abstract:
We report the formation of a nonlayered tellurene monolayer in its alpha-phase through an anisotropic ultrasonication method. The nonlayered tellurene has so far been predicted to exhibit a topologically insulating state of matter in two-dimensional (2D) form with an insulating interior and metallic edge states propagating along the perimeter of the 2D objects. In this work, we report direct evidence of elemental topological insulator behavior in the material through a localized mode of measurement, that is, scanning tunneling spectroscopic studies. We moreover deliberate on the length scale the time-reversal symmetry-protected edge states extend towards the interior. The metallic edge, which has been found to span over a 3 nm region, opens and widens monotonically into gapped states. The appearance of the elemental 2D topological insulator phase has been explained in terms of built-in strains in the systems as viewed through a shift in the Raman modes.
Related Concept Videos
The Evidence for Evolution
2D NMR: Homonuclear Correlation Spectroscopy (COSY)
Conductors and Insulators
Most metals are conductors. Their atomic configuration is such that one or more electron(s) are loosely bound to the nucleus in each atom. Thus, a sea of mobile electrons are available in them, known as free electrons. Their easy...
Insulation Coordination
Elements and Compounds
Elements
Elements are classified as atomic or molecular based on the nature of their basic units. They are unique forms of matter with specific chemical and physical properties that cannot break down into smaller substances by ordinary chemical reactions. There...
2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)

