Cavity Femtochemistry: Manipulating Nonadiabatic Dynamics at Avoided Crossings

Abstract

Molecular potential energy surfaces can be actively manipulated by light. This is usually done by strong classical laser light but was recently demonstrated for the quantum field in an optical cavity. The photonic vacuum state of a localized cavity mode can be strongly mixed with the molecular degrees of freedom to create hybrid field-matter states known as polaritons. We simulate the avoided crossing of sodium iodide in a cavity by incorporating the quantized cavity field into the nuclear wave packet dynamics calculation. The quantized field is represented on a numerical grid in quadrature space, thus avoiding the limitations set by the rotating wave approximation (RWA) when the field is expanded in Fock space. This approach allows the investigation of cavity couplings in the vicinity of naturally occurring avoided crossings and conical intersections, which is too expensive in the fock space expansion when the RWA does not apply. Numerical results show how the branching ratio between the covalent and ionic dissociation channels can be strongly manipulated by the optical cavity.

Three-player polaritons: nonadiabatic fingerprints in an entangled atom–molecule–photon system

“…Polaritonic chemistry has become an emerging research field, aimed at providing new tools for the fundamental investigation of light-matter interaction. Since the pioneering experimental work carried out by the group of Ebbesen, in which they observed that strong light-matter coupling could modify chemical landscapes [8], the field of 'molecular polaritons' experienced much activity from both experimental [9][10][11][12][13][14][15][16][17][18][19] and theoretical [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] research groups. Recent achievements on molecules strongly coupled to a cavity mode, such as that strong cavity-matter coupling can alter chemical reactivity [9,38], provide long-range energy or charge transfer mechanisms [12,37], modify nonradiative relaxation pathways through collective effects [35], and modify the optical response of molecules [31,40], support the relevance of such a new chemistry.…”

“…In such theoretical descriptions, the molecules are usually treated with a reduced number of degrees of freedom or with some simplified models assuming two-level systems [20]. However, it is worth studying single-molecule cavity interactions as well, since a more detailed study of individual objects may also provide meaningful results [22,23,[40][41][42].…”

Different flavors of nonadiabatic molecular dynamics

“…Nonadiabatic molecular dynamics combined with machine‐learning strategies for the calculation of electronic‐structure quantities has recently emerged . Quantum electrodynamics effects have been introduced in nonadiabatic dynamics to investigate, for example, molecular dynamics in an optical cavity or the description of stimulated emission processes …”

Proton Spin‐Lattice Relaxation in Organic Molecular Solids: Polymorphism and the Dependence on Sample Preparation

“…The relationship between V and E is complicated and numerical models suggest that E is between 0 and 20 % smaller than V for activation energies E in the range being investigated here. [87,88] For 2-ethylanthracene (sample EA1), E DC = 16.0 AE 1.6 kJ mol À1 , e = 0.53 AE 0.11, y = 1.6 AE 0.3, and x = 0.30 AE 0.15. For 2-ethylanthraquinone (sample EAQ1), E DC = 17.5 AE 1.8 kJ mol À1 , e = 0.60 AE 0.12, y = 1.3 AE 0.3 and x = 0.50 AE 0.25.…”