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Kim LY, Park S, Lee CY, Schöllkopf W, Zhao BS. Enhanced elastic scattering of He 2 and He 3 from solids by multiple-edge diffraction. Phys Chem Chem Phys 2022; 24:21593-21600. [PMID: 35971780 DOI: 10.1039/d2cp02641d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report on a method of enhanced elastic and coherent reflection of 4He2 and 4He3 from a micro-structured solid surface under grazing incidence conditions. The van der Waals bound ground-state helium clusters exhibit fundamental quantum effects: 4He2, characterized by a single ro-vibrational bound state of 10-7 eV dissociation energy, is known to be a quantum halo state; and 4He3 is the only electronic ground-state triatomic system possessing an Efimov state in addition to the ro-vibrational ground state. Classical methods to select and manipulate these clusters by interaction with a solid surface fail due to their exceedingly fragile bonds. Quantum reflection under grazing incidence conditions was demonstrated as a viable tool for elastic scattering from a solid surface but suffers from small reflection probabilities for typical conditions. Here we demonstrate that multiple-edge diffraction enables enhanced elastic scattering of the clusters from a solid. A dual-period reflection grating, where the strips consist of micro-structured edge arrays, shows an up to ten fold increased reflection probability as compared to its conventional counterpart where the strips are plane patches enabling quantum reflection of the clusters. The observed diffraction patterns of the clusters provide evidence of the coherent and elastic nature of scattering by multiple-edge diffraction.
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Affiliation(s)
- Lee Yeong Kim
- Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, South Korea.
| | - Sanghwan Park
- Department of Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, South Korea
| | - Chang Young Lee
- Department of Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, South Korea
| | - Wieland Schöllkopf
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany.
| | - Bum Suk Zhao
- Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, South Korea. .,Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, South Korea
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Kurz N, Fischer D, Pfeifer T, Dorn A. Reaction microscope for investigating ionization dynamics of weakly bound alkali dimers. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:123202. [PMID: 34972432 DOI: 10.1063/5.0069506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 11/12/2021] [Indexed: 06/14/2023]
Abstract
We report on the implementation of a far-off-resonant, optical dipole force trap in a reaction microscope combined with a magneto-optical trap. Kinematically complete multi-photon ionization experiments were performed on optically trapped 6Li atoms and photo-associated 6Li2 molecules in their highest vibrational state. The apparatus allows us to distinguish different ionization mechanisms related to the presence of the IR field of the optical dipole trap that can occur during ionization of 6Li and 6Li2 in strong fields. In a series of proof-of-principle experiments, we detect weakly bound dimers via three-photon ionization with femtosecond pulses (τ = 30 fs) at a central wavelength of 780 nm and measure directly the momenta of the photoelectrons in coincidence with recoil ions.
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Affiliation(s)
- N Kurz
- Max-Planck Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - D Fischer
- Physics Department and LAMOR, Missouri University of Science and Technology, Rolla, Missouri 65409, USA
| | - T Pfeifer
- Max-Planck Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - A Dorn
- Max-Planck Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
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Pendular alignment and strong chemical binding are induced in helium dimer molecules by intense laser fields. Proc Natl Acad Sci U S A 2018; 115:E9058-E9066. [PMID: 30194233 DOI: 10.1073/pnas.1810102115] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Intense pulsed-laser fields have provided means to both induce spatial alignment of molecules and enhance strength of chemical bonds. The duration of the laser field typically ranges from hundreds of picoseconds to a few femtoseconds. Accordingly, the induced "laser-dressed" properties can be adiabatic, existing only during the pulse, or nonadiabatic, persisting into the subsequent field-free domain. We exemplify these aspects by treating the helium dimer, in its ground [Formula: see text] and first excited [Formula: see text] electronic states. The ground-state dimer when field-free is barely bound, so very responsive to electric fields. We examine two laser realms, designated (I) "intrusive" and (II) "impelling." I employs intense nonresonant laser fields, not strong enough to dislodge electrons, yet interact with the dimer polarizability to induce binding and pendular states in which the dimer axis librates about the electric field direction. II employs superintense high-frequency fields that impel the electrons to undergo quiver oscillations, which interact with the intrinsic Coulomb forces to form an effective binding potential. The dimer bond then becomes much stronger. For I, we map laser-induced pendular alignment within the X state, which is absent for the field-free dimer. For II, we evaluate vibronic transitions from the X to A states, governed by the amplitude of the quiver oscillations.
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Redchenko ES, Lemeshko M. Libration of Strongly‐Oriented Polar Molecules inside a Superfluid. Chemphyschem 2016; 17:3649-3654. [DOI: 10.1002/cphc.201601042] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Indexed: 11/06/2022]
Affiliation(s)
- E. S. Redchenko
- IST Austria (Institute of Science and Technology Austria) Am Campus 1 3400 Klosterneuburg Austria
| | - Mikhail Lemeshko
- IST Austria (Institute of Science and Technology Austria) Am Campus 1 3400 Klosterneuburg Austria
- Kavli Institute for Theoretical Physics University of California Santa Barbara CA 93106 USA
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Tomza M, González-Férez R, Koch CP, Moszynski R. Controlling magnetic Feshbach resonances in polar open-shell molecules with nonresonant light. PHYSICAL REVIEW LETTERS 2014; 112:113201. [PMID: 24702365 DOI: 10.1103/physrevlett.112.113201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Indexed: 06/03/2023]
Abstract
Magnetically tunable Feshbach resonances for polar paramagnetic ground-state diatomics are too narrow to allow for magnetoassociation starting from trapped, ultracold atoms. We show that nonresonant light can be used to engineer the Feshbach resonances in their position and width. For nonresonant field intensities of the order of 10(9) W/cm(2), we find the width to be increased by 3 orders of magnitude, reaching a few Gauss. This opens the way for producing ultracold molecules with sizable electric and magnetic dipole moments and thus for many-body quantum simulations with such particles.
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Affiliation(s)
- Michał Tomza
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland and Instituto 'Carlos I' de Física Teórica y Computacional and Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada, 18071 Granada, Spain and Theoretische Physik, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Rosario González-Férez
- Instituto 'Carlos I' de Física Teórica y Computacional and Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada, 18071 Granada, Spain and The Hamburg Center for Ultrafast Imaging, University of Hamburg, 22761 Hamburg, Germany
| | - Christiane P Koch
- Theoretische Physik, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Robert Moszynski
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
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Affiliation(s)
- Mikhail Lemeshko
- a ITAMP, Harvard-Smithsonian Center for Astrophysics , Cambridge , MA , 02138 , USA
- b Physics Department , Harvard University , Cambridge , MA , 02138 , USA
- c Kavli Institute for Theoretical Physics , University of California , Santa Barbara , CA , 93106 , USA
| | - Roman V. Krems
- c Kavli Institute for Theoretical Physics , University of California , Santa Barbara , CA , 93106 , USA
- d Department of Chemistry , University of British Columbia , BC V6T 1Z1, Vancouver , Canada
| | - John M. Doyle
- b Physics Department , Harvard University , Cambridge , MA , 02138 , USA
| | - Sabre Kais
- e Departments of Chemistry and Physics , Purdue University , West Lafayette , IN , 47907 , USA
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List of publications of Bretislav Friedrich. Mol Phys 2013. [DOI: 10.1080/00268976.2013.792470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Zhao BS, Zhang W, Schöllkopf W. Non-destructive quantum reflection of helium dimers and trimers from a plane ruled grating. Mol Phys 2013. [DOI: 10.1080/00268976.2013.787150] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Bum Suk Zhao
- a School of Nano-Bioscience and Chemical Engineering , Ulsan National Institute of Science and Technology (UNIST) , Ulsan , 689-798 , Korea
| | - Weiqing Zhang
- b Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6 , Berlin , 14195 , Germany
| | - Wieland Schöllkopf
- b Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6 , Berlin , 14195 , Germany
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Affiliation(s)
- J. Peter Toennies
- a Max-Planck-Institut für Dynamik und Selbstorganisation , Göttingen , Germany
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Lemeshko M, Friedrich B. Fine-Tuning Molecular Energy Levels by Nonresonant Laser Pulses. J Phys Chem A 2010; 114:9848-54. [DOI: 10.1021/jp1032299] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mikhail Lemeshko
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Bretislav Friedrich
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
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