Coherent Control of Penning and Associative Ionization: Insights from Symmetries

Abstract

Coherent control of reactive atomic and molecular collision processes remains elusive experimentally due to quantum interference-based requirements. Here, with insights from symmetry conditions, a viable method for controlling Penning and Associative ionization in atomic collisions is proposed. Computational applications to He * ( 3 S)-Li( 2 S) and Ne * ( 3 P2)-Ar( 1 S0) show extensive control over the ionization processes under experimentally feasible conditions.

Preparation of individual magnetic sub-levels of $^4$He($2^3$S$_1$) in a supersonic beam using laser optical pumping and magnetic hexapole focusing

“…Furthermore, magnetic-sub-levelselected beams of He(2 3 S 1 ) are useful as a starting point for the generation of coherent superposition states. The coherent control of Penning and associative ionization cross sections with such superposition states, for instance, involving the M J = 0 sub-level of He(2 3 S 1 ), has been predicted [55]. In addition to that, helium is of particular interest for high-precision tests of few-electron quantum electrodynamics theory, as it is the simplest two-electron atom [56,57].…”

Coherent control mechanisms of Penning and associative ionization in cold He$^*({2}^3\text{S})$-He$^*({2}^3\text{S})$ reactive scattering

“…The ionic molecular states 2 Σ + u and 2 Σ + g are described by the analytical potentials of V + (R) taken from [37]. The real part of the optical potentials, V (R), for R ∈ [3,14) is obtained by interpolating the data in Table 3 of Ref. [29].…”

“…Coherent control [13] is a promising technique for manipulating ultracold atomic [14] and molecular [15] scattering dynamics by initiating scattering in a quantum superposition of internal states, [16,17] which leads to constructive and destructive interference between the different indistinguishable scattering pathways, affecting the outcome of the dynamical process [13]. Initially applied to laser-driven unimolecular processes such as photodissociation, coherent control has enjoyed much success when applied to a wide range of molecular processes.…”

“…Recent theoretical and experimental studies demonstrated efficient quantum state control of product channel branching in Penning ionization * juan.omiste@uam.es (PI) and associative ionization (AI) in cold collisions of ground-state Ar atoms with metastable Ne * [18]. Additional theoretical studies have explored coherent control of cold Ar + Ne * collisions, stressing the important role of rotational symmetry [14,19,20]. (See, however, Ref.…”

“…Our previous work [14,19,20] has focused on coherent control of cold collisions of metastable and groundstate rare-gas atoms such as Ne * ( 3 P 2 ) + Ar, raising the question of whether low-temperature collisions of two metastable atoms such as He * + He * or Ne * + Ne * can be efficiently controlled using quantum superpositions. Such collisions play a key role in evaporative cooling of trapped metastable rare-gas atoms [2,22].…”