Enhanced ionisation of polyatomic molecules in intense laser pulses is due to energy upshift and field coupling of multiple orbitals

Erattupuzha S, Covington CL, Russakoff A, Lotstedt E, Larimian S, Hanus V, Bubin S, Koch M, Gräfe S, Baltuska A, Xie X, Yamanouchi K, Varga K, Kitzler M (2017)

Publication Type: Journal article

Publication year: 2017

Journal

Journal of Physics B-Atomic Molecular and Optical Physics Institute of Physics: Hybrid Open Access

Book Volume: 50

Article Number: 125601

Journal Issue: 12

DOI: 10.1088/1361-6455/aa7098

Abstract

We present the results of a combined experimental and numerical study on strong-field ionisation of acetylene performed with the aim of identifying the mechanism behind the previously reported surprisingly large multi-electron ionisation probabilities of polyatomic molecules. Using coincidence momentum imaging techniques and time-dependent density functional simulations, we show that the reported efficient ionisation is due to the combined action of a significant geometrically induced energy upshift of the most relevant valence orbitals as the C-H distance stretches beyond about two times the equilibrium distance, and a strong increase in the coupling between multiple molecular orbitals concomitant with this stretch motion. The identified enhanced ionisation mechanism, which we refer to as EIC-MOUSE, is only effective for molecules aligned close to parallel to the laser polarisation direction, and is inhibited for perpendicularly aligned molecules because of a suppression of the C-H stretch motion during the onset of ionisation.

Involved external institutions

Technische Universität Wien / Vienna University of Technology AT Austria (AT) Vanderbilt University US United States (USA) (US) University of Tokyo JP Japan (JP) Nazarbayev University / Назарбаев Университеті KZ Kazakhstan (KZ) Technische Universität Graz AT Austria (AT) Friedrich-Schiller-Universität Jena DE Germany (DE)

How to cite

APA:

Erattupuzha, S., Covington, C.L., Russakoff, A., Lotstedt, E., Larimian, S., Hanus, V.,... Kitzler, M. (2017). Enhanced ionisation of polyatomic molecules in intense laser pulses is due to energy upshift and field coupling of multiple orbitals. Journal of Physics B-Atomic Molecular and Optical Physics, 50(12). https://doi.org/10.1088/1361-6455/aa7098

MLA:

Erattupuzha, Sonia, et al. "Enhanced ionisation of polyatomic molecules in intense laser pulses is due to energy upshift and field coupling of multiple orbitals." Journal of Physics B-Atomic Molecular and Optical Physics 50.12 (2017).

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