Topological proximity effect in a topological insulator hybrid

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Topologically protected gapless states are known at topological insulator-insulator interfaces.
• The behavior of topological insulators at interfaces with metals remains largely unexplored.

Purpose of the Study:

• To investigate the physics of interfaces between topological insulators and metals.
• To explore the novel phenomenon of the topological proximity effect.

Main Methods:

• Studied a one-bilayer bismuth (Bi) metal film on a three-dimensional topological insulator (TlBiSe2).
• Utilized spin- and angle-resolved photoemission spectroscopy (SARPES).
• Performed first-principles calculations.

Main Results:

• Observed the migration of the topological Dirac-cone state from the TlBiSe2 surface to the Bi film.
• Demonstrated that this migration results from strong spin-dependent wave function hybridization at the interface.

Conclusions:

• The topological proximity effect enables the transfer of topological states to adjacent metallic films.
• This finding opens new avenues for manipulating topological material properties.