Semi-classical explanation for the dissociation control of H₂⁺

Abstract

A semi-classical model is utilized to explain the dissociation control of the hydrogen molecular ion (H + 2 ). By analyzing the curve of the dissociation asymmetry parameter as a function of the time delay between the exciting and steering pulses, we find that the dissociation control is dependent not only on the peak intensity and direction of the electric field of the steering pulse, but also on the peak intensity of the exciting pulse.

Control of electron localization in the dissociation of and its isotopes with a THz pulse

“…As shown in Refs. [17] and [18], the electron localization by using two laser pulses of UV and THz spectral regimes can be much higher than that in the previous work [13] because there is an effective time for controlling the molecular dissociation. The half period of the control electric field needs to match the effective time of the molecule dissociation if a high control ratio is achieved.…”

“…With the increase of E 20 , some electrons are excited onto the higher 3sσ state through the 3-photon resonance, which dramatically damages the electron localization control. [18]…”

“…For H + 2 , this effective time is about 16.0 fs, and when all the electrons of the dissociative states are excited onto the 2pσ u state, the dissociation control is implemented more easily. With the coupled equations, the same result can be obtained as with the TDSE [18] . So below, we use the coupled equations to investigate the effective time of homo-nuclear molecules with different masses.…”

“…[13] More recently, a similar electron localization probability was obtained by using two-color mid-and nearinfrared laser pulses. [16] In our previous work, [17,18] a time-delayed terahertz (THz) pulse was utilized to steer the electron motion of H + 2 be-tween the two protons after an ultrashort UV laser pulse was used to excite the electron wave packet onto the dissociative 2pσ u state. [19][20][21][22][23][24] Both the THz and the UV pulses were linearly polarized.…”

Selection of quantum path in high-order harmonics and isolated sub-100 attosecond generation in few-cycle spatially inhomogeneous laser fields

“…Numerical approaches to study and control electronic processes in atoms and molecules are largely based on the assumption that the laser electric field is homogeneous in the region where the electron dynamics takes place. [8][9][10][11] Recently, research in laser-atom interaction and as pulses has been created in spatially inhomogeneous fields. [12][13][14] Pérez-Hernández et al [15] solved the three-dimensional timedependent Schrödinger equation in the length gauge by employing a double-pulse, inhomogeneous driving laser field, to show that the combination of temporal and spatial laser field synthesis results in a dramatic cutoff extension that is far beyond the usual semi-classical limit.…”