Scientists experimentally observed topological insulator surface currents

2021-05-09

According to a report from the Science Daily, according to a scientific report, German scientists reported that they experimentally observed the passage of current through the surface of a topological insulator crystal. This channel is less than 1 nanometer wide and extends along the atomic steps of the crystal lattice. The scientists also demonstrated how to introduce these atomic steps in any arrangement. Topological insulators are a hot topic in materials physics. The most significant characteristic of these materials is that they can act as both conductors and insulators, their internal resistance to the passage of current and the edge or surface allows the movement of charge.

German scientists experimentally observe the current flowing through the surface of topological insulator crystals

German scientists at Aachen University of Technology in Germany, the German Research Center, Dresden University of Technology, and the Leibniz Institute for Solids and Materials report that the surface currents of the topological insulators move along tiny channels, which have been theories Calculated and experimentally observed. Their study was published in the March 2nd issue of Nature Physics.

They show that for 铋-铑-iodine crystals, these channels are connected to one-dimensional space surface features and move along the atomic steps formed at the edge of the atomic layer. Scanning tunnel spectra show that the electron channels are continuous in the energy and spatial directions and are less than 1 nanometer wide.

Taking into account the characteristics of the topological insulator, the current is unobstructed in these channels, and the charge can hardly move between the channels. This approach results in the topological insulator surface corresponding to a set of wires defined by the atomic steps of the crystal surface. The scientists demonstrated that this surface can form any arrangement, which allows the channel network to match the nanometer accuracy.

This channel current allows electron transfer while preventing the typical "dispersion" caused by energy consumption, which means that the electrons deviate from their own orbit. As a result, the energy loss and heat generated are greatly reduced. These properties lead to topological insulators or can be applied to electronics. In addition, they will also contribute to new types of information processing, such as spintronics or quantum computing. However, the prerequisite for the development of new devices based on topological insulators is a deep understanding of these quantum phenomena. The recently published article is a landmark step in this direction.

For more than a decade, scientists around the world have investigated and described the transmission of topological insulators. The scientific team led by Professor Michael Ruck of Dresden University of Technology in 2013 succeeded in cultivating a single crystal of iridium-iodine-iodine for the first time. Working with scientists at the Leibniz Institute of Solids and Materials, Germany, they concluded that these crystals are topological insulators with conductive channels. The latest experiment conducted at Aachen University of Technology in Germany, together with calculations at Dresden University of Technology, confirmed this hypothesis.