Ambipolar Superconductivity with Strong Pairing Interaction in Monolayer 1T'-MoTe₂

Area of Science:

• Condensed Matter Physics
• Materials Science
• Superconductivity

Background:

• Gate-tunable two-dimensional (2D) superconductors are crucial for investigating superconducting phase transitions.
• Exfoliated 1T'-MoTe2 monolayers possess an intrinsic band gap of approximately 7.3 meV.

Purpose of the Study:

• To explore superconductivity in exfoliated 1T'-MoTe2 monolayers using field-effect doping.
• To investigate the behavior of superconductivity in both electron and hole doping regimes.

Main Methods:

• Field-effect doping of exfoliated 1T'-MoTe2 monolayers.
• Point-contact spectroscopy to extract superconducting gap information.

Main Results:

• Superconductivity achieved for both electrons and holes in 1T'-MoTe2 monolayers, with onset near 7-8 K.
• Enhanced in-plane upper critical field, exceeding the BCS Pauli limit for both carrier types.
• Superconducting gap ratio significantly larger than BCS weak-coupling predictions.

Conclusions:

• 1T'-MoTe2 monolayers exhibit robust superconductivity tunable by gate doping.
• Observations indicate a strong enhancement of the pairing interaction in this 2D material.
• Results suggest potential for novel superconducting applications in 2D materials.