Long-Range Coulomb Effect in Intense Laser-Driven Photoelectron Dynamics

Abstract

In strong field atomic physics community, long-range Coulomb interaction has for a long time been overlooked and its significant role in intense laser-driven photoelectron dynamics eluded experimental observations. Here we report an experimental investigation of the effect of long-range Coulomb potential on the dynamics of near-zero-momentum photoelectrons produced in photo-ionization process of noble gas atoms in intense midinfrared laser pulses. By exploring the dependence of photoelectron distributions near zero momentum on laser intensity and wavelength, we unambiguously demonstrate that the long-range tail of the Coulomb potential (i.e., up to several hundreds atomic units) plays an important role in determining the photoelectron dynamics after the pulse ends.

Coulomb-corrected quantum interference in above-threshold ionization: Working towards multitrajectory electron holography

“…(22)- (26) and C(t s ) is given by Eq. (11). In practice, we employ the stability factor ∂p s (t)/∂p s (t s ), which is obtained using a Legendre transformation.…”

“…Since the mid-2000s, however, many features stemming from the interplay between the residual binding potential and the laser field have been identified in experiments. Examples are (i) the low-energy enhancements in above-threshold ionization (ATI) spectra [2][3][4][5][6][7][8][9][10][11][12], (ii) the fan-shaped structure in angular resolved ATI electron momentum distributions [13][14][15], and (iii) the species dependency in nonsequential double ionization (NSDI) with circularly polarized fields [16].…”

Near-threshold photoelectron holography beyond the strong-field approximation

“…Holographic patterns are usually understood within the strong-field approximation (SFA) [1,2], or semiclassical models in which the influence of the ionic Coulomb potential on the dynamics of the ionized electron is fully neglected [11,12]. Recently, however, the Coulomb potential has been found to play an important role in the photoelectron spectra, leading to, e.g., an unexpected low-energy structure [17][18][19][20][21] and even a zero-energy structure [22,23]. The Coulomb potential also modifies the holographic patterns, resulting in, e.g., the reduced fringe spacing in the spiderlike holographic structure [6,7] and the appearance of the clear backscattering holography due to the Coulomb focusing [11][12][13].…”

Impact of Coulomb potential on peak structures arising in momentum and low-energy photoelectron spectra produced in strong-field ionization of laser-irradiated atoms

“…With all of the above reasons in mind, the strong-field atomic physics community nowadays came to wellacknowledged and commonly accepted viewpoint that a deeper insight about the origin of phenomena of LES and multi-peak PMD (as well as their adequate description and identification an underlying physical mechanism) can be gained and reached only within those strong-field models and approaches which somehow (though, substantially) take the effects of long-range Coulomb field into proper account [15][16][17][18][19][20][21][22][23][24][25][26][27][28]. So, within the semiclassical model proposed and developed in [15], the double-peak structure in longitudinal PMD arising due to ionization of He atom were attributed to the well-known mechanism of rescattering of emitted photoelectrons on a residual ionic core, while the alternative studies applying a different (viz., quasiclassical trajectory) method [16] suggest that the similar structures arising in PMD under hydrogen ionization is a clear signature of the long-range Coulomb potential of residual ion substantially affecting the trajectories of outgoing photoelectron, though with no any rescattering taken into account.…”

“…The latter progress in understanding the LES phenomenon and underlying physics also gave a new impetus to theoretical and experimental studies of double-peak structure arising in low-momentum domain of PMD (as well as clarification of the underlying physics behind this phenomenon), according to which the LES and double-peak structure proved to be closely related to each other through the same origin and predominantly contributing physical mechanism [23][24][25][26]. Therefore it seems to be natural that the various physical mechanisms proposed to describe the LES phenomenon can be also applied and succeeded in adequate treatment and interpretation of the double-peak structure, for example, within semiclassical approaches [21,27,28], which attributed the emergence of LES to multiple forward-scattering of the direct photoelectrons on the Coulomb field of the residual ionic core under tunneling process. On the other hand, the LES was reliably established to have an universal structure observed under ionization of both atoms and/or molecules [8,12], whereas the double-peak structure in PMD is not always manifested properly, in particular, it does not appear in Ar atom [5,6].…”