Nonadiabatic dynamics in multidimensional complex potential energy surfaces

Abstract

Despite the continuous development of methods for describing nonadiabatic dynamics, there is a lack of multidimensional approaches for processes where the wave function norm is not conserved. A new surface hopping variant closes this knowledge gap.

The role of cavity losses on non-adiabatic couplings and dynamics in polaritonic chemistry

“…The inferences made based on analysis of the features of the γ-dependent polaritonic structure are confirmed by FSSH dynamics 20,21,[34][35][36][37] simulating the polaritonic isomerization across a range of cavity loss values between 0.01 and 1000 meV (equivalently, cavity lifetimes between 0.0006 and 63 ps). Loss values of 100 meV are typical of plasmonic cavities, while the low-loss cases could be realized in dielectric micro-resonators.…”

“…12,[27][28][29][30][31][32] Here we couple a non-Hermitian CQED Hamiltonian 22,23,33 to a model Hamiltonian for the molecular electronic structure of azobenzene to simulate the polaritonic structure and dynamics with ex-plicit inclusion of finite cavity lifetimes. We utilize FSSH dynamics 17,20,21,[34][35][36][37] with potential energy surfaces and non-adiabatic couplings from our non-Hermitian polaritonic structure theory to elucidate the impact of cavity lifetime on the isomerization dynamics under other cavity parameters previously found to facilitate facile cis-to-trans isomerization. 8,17 Several independent contemporaneous studies have leveraged non-Hermitian Hamiltonians to investigate cavity losses in polaritonic chemistry.…”

“…23 Additionally, Kossoski and Barbatti independently developed and rigorously validated a complexsurface FSSH method and demonstrated its applicability in the context of dissociative electron attachment dynamics. 37 A important contribution of our non-Hermitian approach is the elucidation of how cavity losses impact upon the polaritonic structure itself, which then impacts the dynamics that occur on one or more polaritonic surfaces. In the model azobenzene system we explore, we find three distinct regimes with respect to the cavity dissipation rate: low dissipation rates (hγ < 10 −0.5 meV, or τ ≡ 1/γ > 2 ps) where polaritonic isomerization to the trans configuration is facile, moderate dissipation rates (10 0.5 < hγ ≤ 10 1.5 meV, or 2 • 10 −1 > τ ≥ 2 • 10 −2 ps) where isomerization to the trans configuration is strongly suppressed, and large dissipation rates (hγ ≥ 10 2 meV or τ ≤ 10 −2.5 ps where the isomerization yield tends to nearly equal likelihood for cis and trans configurations similar to the photoisomerization of lone azobenzene (see Figure S1 in the Supporting Information).…”

“…We track the nuclear motion along a single reactive coordinate R using FSSH dynamics; 17,20,21,[34][35][36][37] details of this approach are provided in the Supporting Information.…”

Theoretical Challenges in Polaritonic Chemistry

“…As such, they are best exploited to describe one to a small number of molecules, as the algorithm fails at grasping collective effects even in the more refined implementations. [111][112][113][114] The failure is due to the inaccurate evaluation of transition probabilities in the presence of many quasi-degenerate states, 115 which is exactly the case typically encountered when many molecules couple to a single cavity mode. 4,116 An additional problem for the current implementations of semiclassical algorithms that may be potentially hindering to polaritonic chemistry is the incapacity of describing tunneling through potential energy surfaces.…”