Spatial Filtering of Interlayer Exciton Ground State in WSe₂/MoS₂ Heterobilayer

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Optics

Background:

• Long-lived interlayer excitons (IXs) in transition metal dichalcogenide (TMD) heterostructures are key for high-temperature excitonic condensates.
• Separating IX ground state emission is crucial for studying correlated excitonic states, like the excitonic Mott insulator.

Purpose of the Study:

• To demonstrate a method for isolating the IX ground state emission in WSe2/MoS2 heterobilayers.
• To enable the investigation of correlated quantum states at elevated temperatures.

Main Methods:

• Utilizing the distinct spatial profiles of different moiré IX modes for separation.
• Analyzing emission energies and spatial distributions to identify IX modes.
• Applying the rate-diffusion model to understand cascading emission dynamics.

Main Results:

• Successfully separated the IX ground state emission from other IX states in WSe2/MoS2 heterobilayers based on spatial characteristics.
• Identified distinct moiré IX modes through their unique energy signatures and spatial distributions.
• Validated the rate-diffusion model for explaining the observed cascading emission patterns.

Conclusions:

• Spatial filtering is an effective technique for isolating the IX ground state emission.
• This method advances the development of tools for realizing correlated quantum states at higher temperatures.
• The findings contribute to the fundamental understanding of excitonic behavior in TMD heterostructures.