Dice Question Streamline Icon: https://streamlinehq.com

Separating 1–0 and 2–1 coherence contributions in the 612 GHz component of the K2 spectrogram

Establish whether the spectral power near 612 GHz in the sliding Fourier transform of ⟨R⟩(t) for K2 in the 1^3 state arises exclusively from the 1–0 vibrational coherence or also includes a contribution from the 2–1 coherence, overcoming the current inability to distinguish these contributions within ~50 GHz spectral resolution.

Information Square Streamline Icon: https://streamlinehq.com

Background

The sliding Fourier transform (SFT) of the K2 ⟨R⟩(t) trace shows a dominant feature at ~612 GHz, but the time-windowing needed for temporal resolution limits spectral resolution to about 50 GHz.

Within this resolution, the authors explicitly state they cannot formally distinguish whether the 612 GHz power arises solely from the 1–0 vibrational coherence or whether the 2–1 coherence also contributes.

References

In addition to the 1-0 coherence with frequency $\nu_{1,0}$ it is also the 2-1 coherence with frequency $\nu_{2,1}$ because within the spectral resolution, $\sim 50$~GHz, defined by the $20$~ps time segments, we cannot formally distinguish between these two contributions.

— Time-resolved Coulomb explosion imaging of vibrational wave packets in alkali dimers on helium nanodroplets (2411.12885 - Jyde et al., 19 Nov 2024) in Section 'Long-term dynamics: Wave packet dephasing' (Sliding Fourier Transform analysis)