Capturing non-Markovian dynamics with the reaction coordinate method

The reaction coordinate (RC) technique is emerging as a significant tool in the study of quantum dissipative dynamics and thermodynamics. With objective to further establish this tool, here we explore what extent method can capture non-Markovian open systems. As case study, focus on pure decoherence model spin coupled harmonic reservoir. We compare measures for non-Markovianity from exact analytical solution simulations based RC at level second-order master equation. find that quantitatively effects strong system-bath coupling structured baths. This rationalized by fact collective bath mode, which made part system, maintains correlations. Lastly, apply our spin-boson regime.