Electrically tunable low-density superconductivity in a monolayer topological insulator.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Phenomena

Background:

• Superconductivity in topological insulators is key to exploring non-Abelian topological states.
• Previous superconductor-insulator switches were limited to topologically trivial systems.

Purpose of the Study:

• To demonstrate reversible electrostatic switching of superconductivity in a topological insulator.
• To establish a material platform for integrating superconducting and topological phases.

Main Methods:

• Fabrication of monolayer tungsten ditelluride (WTe2) into a van der Waals field-effect transistor.
• In situ electrostatic gating to tune the material's ground state.

Main Results:

• Achieved reversible on-off switching of superconductivity in monolayer WTe2.
• Demonstrated continuous gate-tuning between topological insulating and superconducting states.
• Observed superconducting critical temperatures (Tc) up to approximately 1 Kelvin.

Conclusions:

• Monolayer WTe2 serves as a viable material platform for novel nanodevices.
• This work opens avenues for engineering devices combining superconductivity and topological states.
• The findings facilitate the search for non-Abelian topological states.