Evidence of Wave-Particle Duality for Single Fast Hydrogen Atoms

Abstract

We report the direct observation of interference effects in a Young's double-slit experiment where the interfering waves are two spatially separated components of the de Broglie wave of single 1.3 MeV hydrogen atoms formed close to either target nucleus in H++H2 electron-transfer collisions. Quantum interference strongly influences the results even though the hydrogen atoms have a de Broglie wavelength, lambda_{dB}, as small as 25 fm.

Two-site double-core-hole states formed when fast protons capture electrons from aligned N2

“…We interpret this as a result of two contributions. First, the general contribution from the electron transfer process itself possibly through a similar projectile interference effects as observed earlier for hydrogen targets [15,17]. Second for the higher atomic target fragment charge states, there is an enhancement for orientations where the molecular axis is (close to) aligned with the projectile trajectory.…”

“…Our observations ressembles this behaviour as is shown in figure 4, where the function f (cosθ) = A + Bcos(aδkcosθ) is fitted to the measured dσ/dcosθ for the atomic fragment ions with A and B as fit parameters. From the fit, we find that B = 0.33A and thus the experimental data in combination with this simple model, which was also used for H 2 target molecules in [17], suggests that there is a higher probability of capture of an electron in an initial gerade state. This surprising result would call for further experimental investigations before any conclusions can be made.…”

“…In earlier studies of transfer and excitation in p + H 2 collisions [15] a similar strong orientation dependence could be explained by the well-defined changes in projectile momentum (and thus deBroglie wavelength) that accompanies the electron capture in the vicinity of either target proton. For capture of a target electron from an initial state of gerade symmetry it was predicted [34,35] and later found [15,17] that constructive interference gives a maximum in the cross section for the transverse orientation of the molecular axis with respect to the incoming projectile direction. The same reasoning predicts that there should be minima due to destructive interferences at specific orientations (θ) given by the momentum gained by the projectile (≈ v P /2, where v P is the projectile velocity) when an electron is captured.…”

“…Much later, similar effects were investigated in more detail by means of a COLTRIMS apparatus where strong interference effects were observed for electron-transfer reactions in H + + H 2 [15] and He 2+ + H 2 [16] collisions as variations in the total projectile neutralisation cross sections with molecular orientation. Further the two-slit interference was demonstrated more directly through measurement of markedly different projectile angular scattering distributions for different molecular orientations in the p + H 2 case [17]. Also in much lower-energy ionatom collisions heavy-particle interference in the form of Stückelberg oscillations have been clearly observed for electron-transfer collisions [18,19].…”

Angular scattering in fast ion–atom electron transfer collisions: projectile wave diffraction and Thomas mechanisms

“…Conceptually, this approach is equivalent to the one which has been used to rationalize observations of projectile wave interference in electron transfer to fast projectiles, H + and He 2+ , from molecular hydrogen targets [22,23].…”