Circular dichroism in molecular-frame photoelectron angular distributions in the dissociative photoionization of H2 and D2 molecules
| Autor: | Pérez Torres, Jhon Fredy, Sanz Vicario, José Luis, Veyrinas, K., Billaud, P., Picard, Y. J., Elkharrat, C., Marggi Poullain, S., Saquet, N., Lebech, M., Houver, J. C., Martín García, Fernando, Dowek, D. |
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| Přispěvatelé: | UAM. Departamento de Química |
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Repositorio Institucional del Instituto Madrileño de Estudios Avanzados en Nanociencia instname Biblos-e Archivo. Repositorio Institucional de la UAM Repositorio UdeA Universidad de Antioquia instacron:Universidad de Antioquia |
| ISSN: | 2010-1511 |
| DOI: | 10.1103/physreva.90.043417 |
| Popis: | The presence of net circular dichroism in the photoionization of nonchiral homonuclear molecules has been put in evidence recently through the measurement of molecular-frame photoelectron angular distributions in dissociative photoionization of H2 [Dowek, Phys. Rev. Lett. 104, 233003 (2010)]. In this work we present a detailed study of circular dichroism in the photoelectron angular distributions of H2 and D2 molecules, oriented perpendicularly to the propagation vector of the circularly polarized light, at different photon energies (20, 27, and 32.5 eV). Circular dichroism in the angular distributions at 20 and to a large extent 27 eV exhibits the usual pattern in which inversion symmetry is preserved. In contrast, at 32.5 eV, the inversion symmetry breaks down, which eventually leads to total circular dichroism after integration over the polar emission angle. Time-dependent ab initio calculations support and explain the observed results for H2 in terms of quantum interferences between direct photoionization and delayed autoionization from the Q1 and Q2 doubly excited states into ionic states (1sσg and 2pσu) of different inversion symmetry. Nevertheless, for D2 at 32.5 eV, there is a particular case where theory and experiment disagree in the magnitude of the symmetry breaking: when D+ ions are produced with an energy of around 5 eV. This reflects the subleties associated to such simple molecules when exposed to this fine scrutiny We are very grateful to L. Nahon and G. Garcia for fruitful cooperation, J. F. Gil for technical support, and the SOLEIL general staff for smoothly operating the facility. We gratefully acknowledge the contribution of S. Lupone and S. Damoy (ISMO). N.S. and D.D. acknowledge the support of the Agence Nationale de la Recherche under ATTOWAVE Contract No. ANR-09-BLAN-0031-01. We also thank Mare Nostrum BSC and CCC-UAM for allocation of computer time. The work was supported by the Spanish Ministerio de Ciencia e Innovación (MICINN) Project No. FIS2010-151127 and ERA-Chemistry Project No. PIM2010EEC-00751, the Spanish Ministerio de Economía y Competitividad (MINECO) Project No. FIS2013-42002-R, the XCHEM Advanced Grant No. GA-290853 of the European Research Council, the European Cooperation in Science and Technology (COST) XLIC Action No. CM1204, and the Vicerrectoría de Investigacion at Universidad de Antioquia (CODI Project No. E01538 and Estrategia de Sostenibilidad 2013-2014) |
| Databáze: | OpenAIRE |
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