High-Temperature Single-Photon Emission From Covalently Functionalized van der Waals Heterostructures

Area of Science:

• Materials Science
• Quantum Optics
• Nanotechnology

Background:

• Two-dimensional (2D) transition metal dichalcogenides (TMDs) like tungsten diselenide (WSe2) exhibit single-photon emission (SPE) from atomic defects, crucial for quantum information.
• Current methods for high-purity SPE in WSe2 are limited to low temperatures (below 30 K), hindering practical applications.

Purpose of the Study:

• To develop a method for achieving high-purity SPE in WSe2 at elevated temperatures.
• To enhance the working temperature range of SPE from WSe2 for quantum information applications.

Main Methods:

• Fabrication of 2D WSe2/graphite heterostructures.
• Covalent diazonium functionalization of the graphite layer.
• Characterization of SPE purity and integrity at various temperatures.

Main Results:

• Achieved high-purity (>90%) SPE in strained WSe2 persisting up to 90 K.
• Maintained single-photon source integrity up to 115 K using WSe2/graphite heterostructures.
• Demonstrated a significant increase in the operational temperature range for SPE.

Conclusions:

• Combining 2D heterostructure engineering with molecular functionalization effectively enhances SPE properties in WSe2.
• This approach overcomes the low-temperature limitation of WSe2 SPE, opening new avenues for quantum technologies.
• Surface functionalization and heterostructure design are versatile strategies for improving quantum emission in 2D materials.