Ultra-high electron mobility unlocked in topological Dirac semimetals

An Australian-led study uses a scanning-tunnelling microscope ‘trick’ to map electronic structure in Na3Bi, seeking an answer to that material’s extremely high electron mobility.

In studying the topological Dirac semimetal, the team found that exchange and correlation effects are crucial to electron speed, and therefore mobility, and thus to the use of this exciting class of materials in future ultra-low energy electronics.

To date, little has been known about the band dispersion of Na3Bi in the conduction band (above the Fermi level), though there have been tantalizing hints that the actual velocity of the electrons is much larger than theoretical predictions.