Robust vibrational coherence protected by a core-shell structure in silver nanoclusters

Area of Science:

• Materials Science
• Quantum Chemistry
• Nanotechnology

Background:

• Vibrational coherence is crucial for light harvesting systems.
• The mechanism of vibrational coherence in metal nanoclusters requires further investigation.

Purpose of the Study:

• To demonstrate and identify the mechanism of robust vibrational coherence in Ag44 core-shell nanoclusters.
• To explore the role of the unique structure in maintaining vibrational coherence.

Main Methods:

• Ultrafast spectroscopy was employed to study vibrational coherence.
• Analysis of vibrational modes and their lifetimes.

Main Results:

• Robust vibrational coherence with a 1 ps lifetime was observed in Ag44 nanoclusters.
• Two specific vibrational modes (2.4 THz and 1.6 THz) of the icosahedral Ag12 core were identified as responsible for coherence.
• The unique matryoshka-like core-shell structure of Ag44 contributes to its robust vibrational coherence compared to Ag29.

Conclusions:

• Unambiguous experimental evidence for multi-layer core-shell structure-protected vibrational coherence under ambient conditions was presented.
• The findings offer a practical strategy for designing highly efficient quantum optoelectronic devices.