Előadó: Souvik Mandal (Wigner FK RMI)
Előadásának címe: Quantized Vibrational Relaxation from Stochastic Non-Markovian System-Bath Dynamics
Dátum: 2025. január 23. csütörtök, 14 óra
Helyszín: 3-as épület tanácsterem
Összefoglaló:
In this work, we explore the non-Markovian relaxation dynamics of a vibrating system interacting with a structured environment. Vibrational relaxation dynamics of an adsorbate coupled to a bath of phonons are simulated using the stochastic multi-configuration time-dependent Hartree (MCTDH) method. Non-Markovian effects arise from partitioning the system-bath interaction into explicit and implicit contributions.
Remarkably, a small number of explicit bath modes suffices to capture the short-time non-Markovian behavior. By imposing a "Markovian closure"
on the weakly coupled explicit bath, we uncover distinct physical regimes of vibrational relaxation with unique signatures.
Ultrafast Excited-State Nonadiabatic Dynamics in Pt(II) Donor−Bridge−Acceptor Assemblies: A Quantum Approach for Optical Control
The ultrafast nonadiabatic dynamics of a Pt(II) donor−bridge−acceptor assembly, representative of a series studied experimentally by the Weinstein group (University of Sheffield), is investigated using wavepacket propagations based on the multiconfiguration time-dependent Hartree (MCTDH) method. Employing electronic structure data from time-dependent density functional theory (TD-DFT), the subpicosecond decay is simulated by solving an 11-electronic-state, multimode problem with up to 18 vibrational modes, incorporating both spin-orbit (SOC) and vibronic couplings. The analysis reveals how specific normal modes drive population transfer between key electronic states, distinguishing spin-orbit and vibronically mediated processes. Notably, selective excitation of the N-benzyl out-of-plane twisting mode enhances the population of donor−acceptor charge-separated (CS) states at the expense of charge-transfer (CT) states, demonstrating the potential for vibrationally selective optical control over nonadiabatic pathways.
