Attosecond-resolved coherent control of zone-folded acoustic phonons in silicon carbide

TL;DR

This paper demonstrates precise coherent control of zone-folded acoustic phonons in silicon carbide using femtosecond pulses, revealing interference effects and modeling the process with a two-level system and Raman interactions.

Contribution

It introduces a method for attosecond-resolved coherent control of high-frequency phonons in SiC and provides an analytical model for off-resonant conditions.

Findings

Amplitude control with 300-attosecond precision

Observation of interference fringe patterns

Model accurately reproduces experimental results

Abstract

Zone-folded acoustic phonons (6 THz) in 4H silicon carbide (SiC) have been coherently excited using a femtosecond near-infrared pulse and measured through transient reflectivity with a pump and probe protocol. Their amplitude is coherently controlled with 300-attoseconds precision and the results show interference fringe patterns due to electronic and phonon interference. The results are well reproduced by a model calculation with two electronic and phonon levels and an impulsive stimulated Raman process. Using the model, we obtain the analytical form of the coherent control scheme at an off-resonant condition.