Robust Emission of Dark Trions in WS₂/WSe₂ Heterostructure

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Optics

Background:

• Spin-forbidden dark trions in monolayer transition-metal dichalcogenides (TMDs) possess unique properties like nonzero charge, spin texture, and long lifetimes.
• These dark trions are promising for quantum simulations and optoelectronics, but require methods for enhanced emission and control.

Purpose of the Study:

• To investigate an all-optical route for manipulating and enhancing the emission of dark trions.
• To explore the role of interlayer charge transfer in dark trion formation.
• To understand the temperature stability and fundamental properties of dark trions.

Main Methods:

• Fabrication of a WSe2/WS2 heterostructure coupled to a silver nanowire plasmonic resonator.
• Optical spectroscopy to observe and analyze dark trion emission.
• Variable temperature measurements to determine emission stability.

Main Results:

• Pronounced emission of WS2 dark trions was observed when coupled to the plasmonic resonator.
• Dark trion emission was sustained up to 230 K, significantly higher than previously reported (100 K).
• Interlayer charge transfer was identified as critical for dark trion formation, which also exhibited valley degree of freedom and linear anisotropy.

Conclusions:

• Plasmonic resonators can effectively enhance and stabilize dark trion emission in TMDs.
• Interlayer charge transfer is a key mechanism in forming these spin-forbidden excitons.
• The enhanced temperature stability and observed properties pave the way for utilizing dark trions in advanced quantum technologies.