Quantum coherent plasmon in silver nanowires: a real-time TDDFT study

Area of Science:

• Condensed matter physics
• Quantum chemistry
• Nanophotonics

Background:

• Theoretical linear absorption spectra suggested a plasmon-like phenomenon in 1D silver nanowires due to coinciding resonant excitations.
• This molecular plasmon concept offers potential for anisotropic nanoplasmonic applications.
• The dynamical behavior of these excitations remained experimentally and theoretically unexplored.

Purpose of the Study:

• To investigate the quantum dynamics of longitudinal and transverse electronic excitations in 1D silver nanowires.
• To confirm the collective and in-phase nature of transverse electronic transitions.
• To understand the formation of coherent wave packets and their role in molecular plasmon resonance.

Main Methods:

• Employed real-time time-dependent density functional theory (RT-TDDFT) to simulate quantum dynamics.
• Analyzed anisotropic electron dynamics.
• Examined the time evolution of one-electron wave functions.

Main Results:

• Quantum dynamics simulations confirmed the collective nature of transverse electronic transitions.
• These transverse transitions were observed to oscillate in-phase.
• Analysis indicated the formation of a coherent wave packet from transverse transitions.

Conclusions:

• The study validates the dynamical aspect of molecular plasmon resonance in 1D silver nanowires.
• Observed in-phase, collective electron dynamics underpin the strong plasmon resonance at the molecular level.
• These findings provide a foundation for developing novel anisotropic nanoplasmonic devices.