Excitation of H2 at large internuclear separation: outer well states and continuum resonances

T. M. Trivikram; E. J. Salumbides; Ch Jungen; W. Ubachs

doi:10.1080/00268976.2019.1599457

Excitation of H₂ at large internuclear separation: outer well states and continuum resonances

T. M. Trivikram
, E. J. Salumbides
, Ch Jungen
, W. Ubachs^*

^*Corresponding author for this work

Research output: Contribution to Journal › Article › Academic › peer-review

Abstract

Bound and free quantum resonances of molecular hydrogen exhibiting wave-function density at large internuclear separation, (Formula presented.) 4–5 a.u., are excited via multi-step laser spectroscopy. Highly excited vibrational levels of H (Formula presented.) are prepared via two-photon UV-photolysis of H (Formula presented.) S. Subsequent two-photon Doppler-free precision measurements are performed connecting (Formula presented.) levels with (Formula presented.) outer-well levels. Detection and spectroscopic labelling of the quantum states is assisted by further laser excitation into the auto-ionisation continuum employing a third UV-laser. Level energies of high rotational states ((Formula presented.)) in the outer-well state (Formula presented.) are accurately determined. The three-laser study demonstrates a method for probing resonances in the H (Formula presented.) ionisation continuum with wave-function density at large internuclear separation (Formula presented.) 4–5 a.u., large angular momenta J, and energy range 131,100–133,000 cm ⁻¹, a hitherto unexplored territory.

Original language	English
Pages (from-to)	2961-2971
Number of pages	11
Journal	Molecular Physics
Volume	117
Issue number	21
Early online date	29 Mar 2019
DOIs	https://doi.org/10.1080/00268976.2019.1599457 https://doi.org/10.1080/00268976.2019.1599457
Publication status	Published - 2 Nov 2019

Funding

WU acknowledges the European Research Council for an ERC Advanced Grant under the European Union's Horizon 2020 research and innovation program (Grant Agreement No 670168). The authors wish to thank Prof. F. Merkt (ETH Zürich) for enlightening discussions.

Funders	Funder number
Horizon 2020 Framework Programme
European Research Council
Horizon 2020	670168

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 7 Affordable and Clean Energy

Keywords

Molecular hydrogen
autoionisation
complex resonance
laser spectroscopy
outer-well states

Access to Document

Persistent URL (handle)

Persistent link

Cite this

@article{ba40aacff4764ed69c17ca91e4a7ad25,

title = "Excitation of H2 at large internuclear separation: outer well states and continuum resonances",

abstract = "Bound and free quantum resonances of molecular hydrogen exhibiting wave-function density at large internuclear separation, (Formula presented.) 4–5 a.u., are excited via multi-step laser spectroscopy. Highly excited vibrational levels of H (Formula presented.) are prepared via two-photon UV-photolysis of H (Formula presented.) S. Subsequent two-photon Doppler-free precision measurements are performed connecting (Formula presented.) levels with (Formula presented.) outer-well levels. Detection and spectroscopic labelling of the quantum states is assisted by further laser excitation into the auto-ionisation continuum employing a third UV-laser. Level energies of high rotational states ((Formula presented.)) in the outer-well state (Formula presented.) are accurately determined. The three-laser study demonstrates a method for probing resonances in the H (Formula presented.) ionisation continuum with wave-function density at large internuclear separation (Formula presented.) 4–5 a.u., large angular momenta J, and energy range 131,100–133,000 cm −1, a hitherto unexplored territory. ",

keywords = "Molecular hydrogen, autoionisation, complex resonance, laser spectroscopy, outer-well states",

author = "Trivikram, \{T. M.\} and Salumbides, \{E. J.\} and Ch Jungen and W. Ubachs",

year = "2019",

month = nov,

day = "2",

doi = "10.1080/00268976.2019.1599457",

language = "English",

volume = "117",

pages = "2961--2971",

journal = "Molecular Physics",

issn = "0026-8976",

publisher = "Taylor and Francis Ltd.",

number = "21",

}

TY - JOUR

T1 - Excitation of H2 at large internuclear separation

T2 - outer well states and continuum resonances

AU - Trivikram, T. M.

AU - Salumbides, E. J.

AU - Jungen, Ch

AU - Ubachs, W.

PY - 2019/11/2

Y1 - 2019/11/2

N2 - Bound and free quantum resonances of molecular hydrogen exhibiting wave-function density at large internuclear separation, (Formula presented.) 4–5 a.u., are excited via multi-step laser spectroscopy. Highly excited vibrational levels of H (Formula presented.) are prepared via two-photon UV-photolysis of H (Formula presented.) S. Subsequent two-photon Doppler-free precision measurements are performed connecting (Formula presented.) levels with (Formula presented.) outer-well levels. Detection and spectroscopic labelling of the quantum states is assisted by further laser excitation into the auto-ionisation continuum employing a third UV-laser. Level energies of high rotational states ((Formula presented.)) in the outer-well state (Formula presented.) are accurately determined. The three-laser study demonstrates a method for probing resonances in the H (Formula presented.) ionisation continuum with wave-function density at large internuclear separation (Formula presented.) 4–5 a.u., large angular momenta J, and energy range 131,100–133,000 cm −1, a hitherto unexplored territory.

AB - Bound and free quantum resonances of molecular hydrogen exhibiting wave-function density at large internuclear separation, (Formula presented.) 4–5 a.u., are excited via multi-step laser spectroscopy. Highly excited vibrational levels of H (Formula presented.) are prepared via two-photon UV-photolysis of H (Formula presented.) S. Subsequent two-photon Doppler-free precision measurements are performed connecting (Formula presented.) levels with (Formula presented.) outer-well levels. Detection and spectroscopic labelling of the quantum states is assisted by further laser excitation into the auto-ionisation continuum employing a third UV-laser. Level energies of high rotational states ((Formula presented.)) in the outer-well state (Formula presented.) are accurately determined. The three-laser study demonstrates a method for probing resonances in the H (Formula presented.) ionisation continuum with wave-function density at large internuclear separation (Formula presented.) 4–5 a.u., large angular momenta J, and energy range 131,100–133,000 cm −1, a hitherto unexplored territory.

KW - Molecular hydrogen

KW - autoionisation

KW - complex resonance

KW - laser spectroscopy

KW - outer-well states

UR - https://www.scopus.com/pages/publications/85063876107

UR - https://www.scopus.com/pages/publications/85063876107#tab=citedBy

U2 - 10.1080/00268976.2019.1599457

DO - 10.1080/00268976.2019.1599457

M3 - Article

SN - 0026-8976

VL - 117

SP - 2961

EP - 2971

JO - Molecular Physics

JF - Molecular Physics

IS - 21

ER -