Superconductivity Induced by Strong Electron-Exciton Coupling in Doped Atomically Thin Semiconductor Heterostructures

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Mechanics

Background:

• Superconductivity in atomically thin materials is a key research area.
• Existing models often focus on phonon-mediated interactions.
• Understanding novel mechanisms is crucial for discovering high-temperature superconductors.

Purpose of the Study:

• To investigate a mechanism for inducing superconductivity in 2D semiconductors mediated by excitons.
• To explore interaction effects beyond traditional phonon-mediated superconductivity.
• To analyze the emergence of a BCS-BEC crossover in such systems.

Main Methods:

• Development of a theoretical model incorporating electron-exciton interactions.
• Analysis of strong-coupling physics, including trions.
• Connection to established Bose and Fermi polaron limits.

Main Results:

• Excitons mediate an effective attraction between electrons.
• The electron-exciton interaction exhibits strong frequency and momentum dependence.
• A BCS-BEC crossover from Cooper pairs to a superfluid of bipolarons is observed.
• Bipolarons remain light, enabling critical temperatures up to 10% of the Fermi temperature.

Conclusions:

• Atomically thin semiconductors with exciton-mediated interactions are promising for high-temperature superconductivity.
• Heterostructures of 2D materials offer a viable platform for realizing superconductivity.
• Critical temperatures can be tuned by electron doping and trion binding energies.