New Possibilities for Topological Superconductivity

Lossless conduction at the edges

Excerpts and salient points ~

Schematic diagram of the experimental setup: An atomically thin layer of tungsten ditelluride is located between two contacts (in silver). Current only flows through the material in very narrow channels at the outer edges. (Image Credit: Department of Physics, University of Basel)
Image:  Schematic diagram of the experimental setup: An atomically thin layer of tungsten ditelluride is located between two contacts (in silver). Current only flows through the material in very narrow channels at the outer edges. (Image Credit: Department of Physics, University of Basel)

+  Atomically thin layers of the semi-metal tungsten ditelluride conduct electricity losslessly along narrow, one-dimensional channels at the crystal edges. The material is therefore a second-order topological insulator. By obtaining experimental proof of this behavior, physicists from the University of Basel have expanded the pool of candidate materials for topological superconductivity. The findings have been published in the journal Nano Letters.

“These observations support theoretical predictions that tungsten ditelluride is a higher-order topological material. This opens up new possibilities for topological superconductivity, which could have applications in areas such as quantum computing,” says Christian Schönenberger, who is investigating topological superconductivity in stacks of certain two-dimensional materials as part of an ERC project.

+  Topological insulators represent a key area of research because they could potentially be used as superconductors in the electronics of the future. Materials of this kind behave like insulators on the inside, whereas their surfaces have metallic properties and conduct electricity. A three-dimensional crystal of a topological insulator therefore conducts electricity on its surface, while no current can flow inside. Moreover, due to quantum mechanics, the conductivity on the surface is almost lossless – the electricity is conducted over long distances without heat generation.

+  In addition to these materials, there is another class known as second-order topological insulators. These three-dimensional crystals have conductive, one-dimensional channels running along only certain crystal edges. Materials of this kind are particularly well suited to potential applications in quantum computing.

Source:  University of Basel.  Prof. Dr. Christian Schönenberger,  Lossless conduction at the edges…

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