Two-Source Double-Slit Interference in Angle-Resolved High-Energy Above-Threshold Ionization Spectra of Diatoms

Abstract

When an electron from a diatomic molecule undergoes tunneling-rescattering ionization, a novel form of destructive interference can be realized that involves all four geometric orbits that are available to the electron when it is freed, because both ionization and rescattering may take place at the same or at different centers. We find experimentally and confirm theoretically that in orientation-averaged angle-resolved high-order above-threshold ionization spectra the corresponding destructive interference is visible for O_{2} but not for N_{2}. This effect is different from the suppression of ionization that is well known to occur for O_{2}.

Periodic Variations in the Wavelength Distributions following Photon Interferences: Analogy with Electron Interferences

“…During the last years, electron interference effects have been widely investigated in electron-and ion-induced ionization [7][8][9][10][11][12][13][14][15][16][17][18], as well as in photoionization [19][20][21][22][23][24][25][26][27] of isolated atoms and molecules. In the electron interference experiments [5][6][7][8][9][10][11][12][13][14][15][19][20][21][22][23], each single electron hits the position-sensitive detector like a particle but traverses the interferometer slits (or scatters on atomic centers) like a wave. Thus, over many repetitions, an interference pattern builds up as oscillations of the intensity I(θ d ) = (dI/dλ)dλ with the observation angle θ d [5][6][7][8][9][10].…”

Direct observation of Young’s double-slit interferences in vibrationally resolved photoionization of diatomic molecules

“…Over the last few years, a substantial experimental effort has been devoted to investigate these two-center interferences in the simplest diatomic molecules, mainly in the context of photoionization [see, e.g., (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)], but also in ionizing collisions with fast ions (18)(19)(20)(21) and electrons (22)(23)(24). However, due to the rapid decrease of σ 0 with photoelectron energy, i.e., with k e , the oscillations are usually hidden and must be uncovered through dividing the total cross section by an independent but arbitrary estimate of σ 0 , leading to equivocal interpretations (18,19).…”

Atoms and Molecules in a Strong Laser Field

“…Dramatically different behavior was found between N 2 (σ g ) and O 2 (π g ) at parallel and perpendicular molecular orientation. This is crucial for explanation of the two--source double-slit destructive interference effect, which has been observed in experiments with randomly oriented O 2 molecules [10].…”

“…By θ L we define angle between the laser polarization vector and internuclear axis, while θ accounts for the angle between final momentum of the detected electron and internuclear axis. This novel two-source two-rescattering-centers interference has been observed in experiments with unaligned molecules [9,10]. Recently, we have shown that for elliptical polarization interference condition (5) still holds [11] but one should have in mind that k st is a complex solution of the saddle-point equations [12,13].…”