ELFT HÍRADÓ

[Papai Matyas <papai.matyas AT wigner.hun-ren.hu>]

Szemináriumi meghívó

HUN-REN Wigner FK Nukleáris Anyagtudományi Osztály (NAO)

Időpont: Jan 23 (csütörtök) 14:00
Helyszín: RMI 3. épület tanácsterem

Souvik Mandal (HUN-REN Wigner FK NAO)

Quantized Vibrational Relaxation from Stochastic Non-Markovian 
System-Bath Dynamics

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.

Minden érdeklődőt szívesen látunk! (kérem, aki szeretné az előadást 
meghallgatni és nincs KFKI belépője, jelezze nekem itt: 
papai.matyas AT wigner.hun-ren.hu)

Üdvözlettel,

Pápai Mátyás