Feshbach Resonances in Exciton-Charge-Carrier Scattering in Semiconductor Bilayers

Area of Science:

• Condensed Matter Physics
• Quantum Optics
• Materials Science

Background:

• Feshbach resonances are crucial for controlling interactions in cold atom systems.
• A solid-state analog was recently observed in transition metal dichalcogenides.
• Controllable interactions are key for advancing semiconductor physics.

Purpose of the Study:

• To demonstrate how tunneling-induced layer hybridization creates Feshbach resonances in 2D semiconductors.
• To show these resonances enable tuning of electron-exciton interactions.
• To explore Bose-Fermi mixtures in solid-state systems.

Main Methods:

• Microscopic scattering theory applied to atomically thin semiconductors.
• Calculation of exciton-electron scattering phase shifts from first principles.
• Analysis of tunneling-induced layer hybridization.

Main Results:

• Two distinct classes of Feshbach resonances emerge due to layer hybridization.
• Electron interactions with both intralayer and interlayer excitons are tunable.
• Exciton-electron coupling can be tuned from strong to vanishing interactions.

Conclusions:

• Atomically thin semiconductors exhibit tunable Feshbach resonances.
• This tunability allows for novel control over quantum interactions in solids.
• Opens possibilities for solid-state Bose-Fermi mixtures analogous to cold atom systems.