Mapping electronic decoherence pathways in molecules

• DOI: 10.1073/pnas.2309987120
• Publication Date: 2023-11-28T18:35:15Z
• Authors: Ignacio Gustin; Chang Woo Kim; David W. McCamant; Ignacio Franco
• Keywords: Chemical Physics (physics.chem-ph); Quantum Physics; Physics - Chemical Physics; Physical Sciences; FOS: Physical sciences; Quantum Physics (quant-ph)

Establishing the fundamental chemical principles that govern molecular electronic quantum decoherence has remained an outstanding challenge. Fundamental questions such as how solvent and intramolecular vibrations or functionalization contribute to remain unanswered are beyond reach of state-of-the-art theoretical experimental approaches. Here we address this challenge by developing a strategy isolate pathways for chromophores immersed in condensed phase environments enables elucidating coherence is lost. For this, first identify resonance Raman spectroscopy general method reconstruct spectral densities with full complexity at room temperature, solvent, fluorescent non-fluorescent molecules. We then show quantitatively capture dynamics from density decomposing overall loss into contributions due individual modes. illustrate utility analyzing DNA base thymine water. Its coherences decay <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mo>∼</mml:mo> </mml:math> 30 fs. The early-time determined while solvent. Chemical substitution modulates hydrogen-bond interactions ring water leading fastest decoherence. Increasing temperature leads faster it enhances importance but leaves intact. developed opens key opportunities establish connection between structure needed develop strategies rationally modulate it.