Holographic detection of parity in atomic and molecular orbitals

Abstract

We introduce a concise methodology to detect the parity of atomic and molecular orbitals based on photoelectron holography, which is more general than the existing schemes. It fully accounts for the Coulomb distortions of electron trajectories, does not require sculpted fields to retrieve phase information and, in principle, is applicable to a broad range of electron momenta. By comparatively measuring the differential photoelectron spectra from strong-field ionization of N 2 molecules and their companion atoms of Ar, some photoelectron holography patterns are found to be dephased for both targets. This is well reproduced by the full-dimensional time-dependent Schrödinger equation and the Coulomb quantum-orbit strong-field approximation (CQSFA) simulation. Using the CQSFA, we trace back our observations to different parities of the 3p orbital of Ar and the highest-occupied molecular orbital of N 2 via interfering Coulomb-distorted quantum orbits carrying different initial phases. This method could in principle be used to extract bound-state phases from any holographic structure, with a wide range of potential applications in recollision physics and spectroscopy.

Spiral-like holographic structures: Unwinding interference carpets of Coulomb-distorted orbits in strong-field ionization

“…Comparing two targets, such as N 2 and neon in Ref. [46], allows the spiral to be exploited as a sensitive probe of orbital parity. It should be noted that recently it has been shown in Ref.…”

“…First, it is visible without any additional manipulation because in the angle-energy region of interest only electron orbits 3 and 4 are dominant. Second, for θ = 90 • , phase differences that are usually hidden can be extracted [46]. Third, these two trajectories revisit the ion core very closely, undergoing strong interaction with the binding potential.…”

“…In contrast to previous calculations [18,[33][34][35]37,46], 1 here we employ the single-electron effective potential [47,48]…”

Dissecting subcycle interference in photoelectron holography

“…Photoelectron vector momentum distributions (PMDs) encode these trajectories as intricate interference patterns displayed in angularly resolved photoelectron measurements. Significant work has been applied towards isolating and disentangling these patterns in order to determine the electron [2,[5][6][7][8][9][10][11][12][13][14][15][16][17] and sometimes the core [18][19][20] dynamics.…”

“…It provides a very clear picture with four interfering "orbits," which may be switched on and off at will. This has enabled computationally fast and accurate analyses of experimental features [15,16].…”