Topological states on the gold surface
Binghai Yan, Benjamin Stadtmueller, Norman Haag, Sebastian Jakobs, Johannes Seidel, Dominik Jungkenn, Stefan Mathias, Mirko Cinchetti, Martin Aeschlimann, Claudia Felser
Research output: Contribution to journal › Article › peer-review
Gold surfaces host special electronic states that have been understood as a prototype of Shockley surface states. These surface states are commonly employed to benchmark the capability of angle-resolved photoemission spectroscopy (ARPES) and scanning tunnelling spectroscopy. Here we show that these Shockley surface states can be reinterpreted as topologically derived surface states (TDSSs) of a topological insulator (TI), a recently discovered quantum state. Based on band structure calculations, the Z(2)-type invariants of gold can be well-defined to characterize a TI. Further, our ARPES measurement validates TDSSs by detecting the dispersion of unoccupied surface states. The same TDSSs are also recognized on surfaces of other well-known noble metals (for example, silver, copper, platinum and palladium), which shines a new light on these long-known surface states.