Pulse overlap ambiguities in multiple quantum coherence spectroscopy

TL;DR

This paper investigates how pulse overlap affects ultrafast spectroscopy measurements, revealing parasitic signals and extended lifetimes that impact data interpretation in quantum coherence studies.

Contribution

It demonstrates the emergence of parasitic multiple-quantum coherence signals due to pulse overlap in two-level systems, highlighting implications for spectroscopy analysis.

Findings

Parasitic multiple-quantum coherence signals arise from pulse overlap.

Signal lifetimes exceed pulse overlap duration by a factor of 1.8.

Implications for interpreting higher-order coherent spectroscopy experiments.

Abstract

Coherent two-dimensional electronic spectroscopy probes ultrafast dynamics using femtosecond pulses. In case the timescale of the studied dynamics become comparable to the pulse duration, pulse overlap effects may compromise the experimental data. Here, we perform one-dimensional coherence scans and study pulse overlap effects in clean two-level systems. We find parasitic multiple-quantum coherence signals as a consequence of the arbitrary time ordering during the temporal pulse overlap. Surprisingly, the signal lifetimes exceed the temporal pulse overlap by a factor of 1.8. These findings have important implications for the interpretation of higher-order coherent two-dimensional and related spectroscopy experiments.