Two-Dimensional Materials as Ideal Substrates for Molecular Quantum Emitters.

Area of Science:

• Quantum optics and photonics
• Materials science for quantum applications
• Computational condensed matter physics

Background:

• Nonclassical states of light are essential for quantum technologies.
• Organic molecules on substrates are promising for single-photon generation due to scalability and tunable emission.
• Previous research focused on color centers in insulators, but organic systems offer advantages.

Purpose of the Study:

• To investigate photoemission from organic molecules adsorbed on 2D materials using first-principles calculations.
• To understand the role of substrate interactions in shaping molecular optical properties.
• To provide insights for designing molecular systems for quantum applications.

Main Methods:

• First-principles calculations (e.g., density functional theory).
• Modeling of terrylene molecules adsorbed on hexagonal boron nitride (hBN).
• Analysis of photoemission spectra, including zero phonon line (ZPL) energies and lineshapes.

Main Results:

• Calculated ZPL energies and emission lineshapes for terrylene on hBN agree well with experimental data.
• Antisite defects in hBN can immobilize molecules without altering their primary emission characteristics.
• The 2D substrate introduces sharp sidebands near the ZPL, indicative of hindered molecular motion (rotational, translational, bending).

Conclusions:

• Substrate interactions significantly influence the optical properties of adsorbed organic molecules.
• Hexagonal boron nitride is a suitable substrate for immobilizing organic emitters without compromising their quantum emission.
• Understanding these substrate-molecule interactions is key to advancing molecular quantum technologies.