Superconducting Material Holds Promise for Quantum Computing

  • By Jenny Stein
  • 14 April 2020

Written by Ben Panko. Read the full article from the CMU Department of Physics.

New research from Carnegie Mellon physicists details the creation of a special kind of superconducting material that could allow for the creation of new and more robust quantum computers.

"The main result is that we created a new state of matter," said Assistant Professor of Physics Ben Hunt, who led the research in collaboration with Professor of Physics Randall Feenstra, Ph.D. candidate Dacen Waters and Felix Lüpke, currently a postdoctoral researcher at the Oak Ridge National Laboratory.

This state of matter, a one-dimensional topological superconductor, has actually been made before, Hunt clarified, but their new study published in the journal Nature Physics proved its first creation in a particular material — tungsten telluride.

On its own, tungsten telluride is a fascinating material. When electricity is conducted through a sheet of it, instead of flowing evenly through the material, the electricity instead only flows around the substance's edges. This unique edge conduction, described as one-dimensional, makes tungsten telluride a topological insulator.

"We knew that this state existed and what we did in this paper is that we took this really interesting edge state and made it go superconducting," Hunt explained.

The researchers did that by sticking the tungsten telluride onto the superconductor niobium diselenide. Using a new scanning tunneling microscope that was funded partially by the Mellon College of Science, the team was able to confirm that by being in proximity to a superconductor, the tungsten telluride gained superconducting properties while still retaining its unique properties.

"To realize this one-dimensional topological superconductor is a fundamental element in building a topological quantum computer," Hunt said. Such topological quantum computers have been theorized to be more robust against normal environmental conditions than currently existing state-of-the-art quantum computers being studied at Google and IBM, potentially allowing quantum computers to be more compact and resilient to errors.   

Other authors on the study included Michael Widom and Sergio C. de la Barrera of Carnegie Mellon's Department of Physics, and David Mandrus and Jiaqiang Yan of the Oak Ridge National Laboratory.