University of Arkansas
Synthesis and Characterization of Helical Crystals of Selenium and Tellurium
The elements selenium and tellurium crystallize as hexagonal arrays of quasi-one-dimensional helical chains that have three atoms per turn. The screw symmetry of the helices has been predicted to generate a number of unusual and useful properties including a giant kinetic magnetoelectric effect and Weyl nodes. Because the Weyl nodes are adjacent to a relatively small (0.3 eV) band gap in tellurium, it may be possible to investigate this topological material in confined geometries and devices via electrostatic gating. In this context, we have synthesized 1D nanowires and 2D flakes of selenium and tellurium by physical vapor deposition as well as exfoliation of bulk crystals. I will also describe initial electronic device characterization that indicates ambipolar transport with a sufficient mobility for quantum transport experiments.