The manifestation of vibrational excitation effect in reactions C + SH(v= 0–20,j= 0) $ \rightarrow $ H + CS, S + CH

Abstract

The dependence of the cross section for the C + SH  H + CS, S + CH reactions on the vibrational excitation of SH(v = 0-20, j = 0) is analyzed in detail at the collision energies of 0.3 and 0.8 eV by using the quasi-classical trajectory method and the new potential energy surface). The efficiency of vibrational excitation to promote the reaction is investigated through the analysis of the cross section and its v dependence in terms of the reaction probability, maximum impact parameter, and the features of the potential energy surface. The differential cross sections obtained show that at higher vibrational levels, the products (CS, CH) are mainly forward scattered, and the sideward and backward scatterings are quite weak. In addition to the scalar properties, the stereodynamical attributes, such as angle distribution functions P(θ r ), P(f r ) and P(θ r , f r ) at different vibrational levels are explored in detail. Furthermore, through the investigation of the state-to-state dynamics for the titled reaction, it is clear that the vibrational excitation of the product for C + SH  H + CS reaction is quite strong, with the most probable population appearing at high vibration numbers.

Rydberg-blockade effects in Autler-Townes spectra of ultracold strontium

“…As a unique feature of our experiment, the long lifetime of the intermediate state enables AT spectroscopy for strongly driven Rydberg transitions, i.e., in the regime of small Rydberg state population similar to EIT experiments in alkali gases. In contrast to previous studies of related alkali systems [37,38,42,45,46,50], our measurements show clear signatures of both level shifts as well as decoherence induced by the strong Rydberg-Rydberg atom interactions. Our theoretical analysis is based on an effective one-body description augmented by nonlinear energy shifts and dephasing rates that are proportional to the Rydberg density and obtained from a meanfield description accounting for excitation blockade effects [56].…”

“…Many of these open questions have been studied via two-photon Rydberg excitation of alkali atoms in a threelevel ladder configuration, where different regimes corresponding to coherent population trapping (CPT) [40,41], electromagnetically induced transparency (EIT) [37,[41][42][43], and Autler-Townes (AT) spectroscopy [44][45][46] can be accessed by varying the relative intensity of the two excitation lasers. For alkali atoms this typically involves a long-lived Rydberg state and a much more rapidly decaying intermediate state, which for example requires a strongly driven low lying transition in order to resolve the structure of AT spectra.…”

“…Previous work studied different regimes and succeeded to describe certain aspects of experiments, e.g., through lowintensity expansions [47], classical Monte Carlo simulations [6,48,49], density-matrix cluster expansions in the limit of low densities [40] or quantum trajectory Monte Carlo simulations of small systems [11,48]. An insightful approach to analyze experimental observation is based on the corresponding single-body optical Bloch equations augmented by additional terms describing interaction induced Rydberg level shifts as well as dephasing of the Rydberg transition [37,38,42,45,46,50]. Depending on the particular setting such measurements where found to be consistent with either interaction induced line shifts [38] or pure dephasing [37,42,45,46,50].…”

“…An insightful approach to analyze experimental observation is based on the corresponding single-body optical Bloch equations augmented by additional terms describing interaction induced Rydberg level shifts as well as dephasing of the Rydberg transition [37,38,42,45,46,50]. Depending on the particular setting such measurements where found to be consistent with either interaction induced line shifts [38] or pure dephasing [37,42,45,46,50].…”

State-to-state dynamics of the C+(2P) + SH(X2Π) → H(2S) + CS+(X2Σ+) reaction using a time-dependent wave packet and quasi-classical trajectory methods

“…The QCT method [22][23][24][25][26][27] has been widely applied to explore chemical reaction dynamics [28][29][30][31][32][33]. Here, only the details pertinent to the present work are summarized.…”