Electrostatic quantum nanocorral for composite charged excitons

Area of Science:

• Quantum physics
• Materials science
• Nanotechnology

Background:

• Tunable interfaces between photons and quantum states are crucial for quantum networks.
• Quantum-confined charged excitons offer single-photon emission and localized charge states but face challenges in nanoscale confinement.
• Previous quantum corrals used scanning tunneling microscopy to arrange adatoms for confining electronic standing waves.

Purpose of the Study:

• To demonstrate luminous, quantum-confined charged excitons in monolayer WSe2.
• To develop a robust, reversible, and spectroscopically resolvable nanoscale electrostatic confinement method.
• To establish an electrically tunable route for controlling charged excitons for quantum light sources.

Main Methods:

• Fabrication of an electrostatic quantum nanocorral using a nanoporous metallic monolayer gate on monolayer WSe2.
• Gating WSe2 through the nanoporous layer to define ~10-nm confinement scales.
• Utilizing scanning tunneling microscopy principles for precise nanoscale structuring.

Main Results:

• Achieved ultrabright charged excitons confined by higher-energy neutral excitons within the nanocorral.
• Observed distinct excitonic quasiparticle states inside and outside the nanopore with pronounced energy splittings.
• Demonstrated dynamic reconfiguration of the electrostatic barrier, enabling a crossover between 0D and 2D excitonic states.
• Polarization-resolved measurements revealed signatures of fine-structure splitting.

Conclusions:

• The electrostatic quantum nanocorral provides an effective method for nanoscale confinement of charged excitons in WSe2.
• This technique enables the creation of quantum light sources with dynamically adjustable brightness, energy, and photon statistics.
• The demonstrated tunable interface is a significant step towards advanced quantum networks and quantum information processing.