Ambipolar Electric Field Effect in Metallic Bi2Se3

Understand

Topological insulators (TIs) constitute a new class of materials with unique properties resulting from the relativistic-like character and topological protection of their surface states.

• Theory predicts these to exhibit a rich variety of physical phenomena such as anomalous magneto-electric coupling and Majorana excitations.
• Although TI surface states have been detected in Bi-based compounds by ARPES and STM techniques, electrical control over their density, required for most transport experiments, remains a challenge.
• Existing materials are heavily doped in the bulk, thus preventing electrical tunability of the surface states and their integration into topological quantum electronic devices.