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Nguyen QLD, Simoni J, Dorney KM, Shi X, Ellis JL, Brooks NJ, Hickstein DD, Grennell AG, Yazdi S, Campbell EEB, Tan LZ, Prendergast D, Daligault J, Kapteyn HC, Murnane MM. Direct Observation of Enhanced Electron-Phonon Coupling in Copper Nanoparticles in the Warm-Dense Matter Regime. PHYSICAL REVIEW LETTERS 2023; 131:085101. [PMID: 37683150 DOI: 10.1103/physrevlett.131.085101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 06/27/2022] [Accepted: 05/26/2023] [Indexed: 09/10/2023]
Abstract
Warm dense matter (WDM) represents a highly excited state that lies at the intersection of solids, plasmas, and liquids and that cannot be described by equilibrium theories. The transient nature of this state when created in a laboratory, as well as the difficulties in probing the strongly coupled interactions between the electrons and the ions, make it challenging to develop a complete understanding of matter in this regime. In this work, by exciting isolated ∼8 nm copper nanoparticles with a femtosecond laser below the ablation threshold, we create uniformly excited WDM. Using photoelectron spectroscopy, we measure the instantaneous electron temperature and extract the electron-ion coupling of the nanoparticle as it undergoes a solid-to-WDM phase transition. By comparing with state-of-the-art theories, we confirm that the superheated nanoparticles lie at the boundary between hot solids and plasmas, with associated strong electron-ion coupling. This is evidenced both by a fast energy loss of electrons to ions, and a strong modulation of the electron temperature induced by strong acoustic breathing modes that change the nanoparticle volume. This work demonstrates a new route for experimental exploration of the exotic properties of WDM.
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Affiliation(s)
- Quynh L D Nguyen
- JILA, Department of Physics, University of Colorado and NIST, Boulder, Colorado 80309, USA
| | - Jacopo Simoni
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Kevin M Dorney
- JILA, Department of Physics, University of Colorado and NIST, Boulder, Colorado 80309, USA
| | - Xun Shi
- JILA, Department of Physics, University of Colorado and NIST, Boulder, Colorado 80309, USA
| | - Jennifer L Ellis
- JILA, Department of Physics, University of Colorado and NIST, Boulder, Colorado 80309, USA
| | - Nathan J Brooks
- JILA, Department of Physics, University of Colorado and NIST, Boulder, Colorado 80309, USA
| | - Daniel D Hickstein
- Kapteyn-Murnane Laboratories Inc., 4775 Walnut St #102, Boulder, Colorado 80301, USA
| | - Amanda G Grennell
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309 80309, USA
| | - Sadegh Yazdi
- Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - Eleanor E B Campbell
- EaStCHEM, School of Chemistry, Edinburgh University, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
- Department of Physics, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Liang Z Tan
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - David Prendergast
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Jerome Daligault
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Henry C Kapteyn
- JILA, Department of Physics, University of Colorado and NIST, Boulder, Colorado 80309, USA
- Kapteyn-Murnane Laboratories Inc., 4775 Walnut St #102, Boulder, Colorado 80301, USA
| | - Margaret M Murnane
- JILA, Department of Physics, University of Colorado and NIST, Boulder, Colorado 80309, USA
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Ru B, Hart CA, Mabbs R, Gozem S, Krylov AI, Sanov A. Dipole effects in the photoelectron angular distributions of the sulfur monoxide anion. Phys Chem Chem Phys 2022; 24:23367-23381. [PMID: 36129043 DOI: 10.1039/d2cp03337b] [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
Photoelectron angular distributions (PADs) in SO- photodetachment using linearly polarized 355 nm (3.49 eV), 532 nm (2.33 eV), and 611 nm (2.03 eV) light were investigated via photoelectron imaging spectroscopy. The measurements at 532 and 611 nm access the X3Σ- and a1Δ electronic states of SO, whereas the measurements at 355 nm also access the b1Σ+ state. In aggregate, the photoelectron anisotropy parameter values follow the general trend with respect to electron kinetic energy (eKE) expected for π*-orbital photodetachment. The trend is similar to O2-, but the minimum of the SO- curve is shifted to smaller eKE. This shift is mainly attributed to the exit-channel interactions of the departing electron with the dipole moment of the neutral SO core, rather than the differing shapes of the SO- and O2- molecular orbitals. Of the several ab initio models considered, two approaches yield good agreement with the experiment: one representing the departing electron as a superposition of eigenfunctions of a point dipole-field Hamiltonian, and another describing the outgoing electron in terms of Coulomb waves originating from two separated charge centers, with a partial positive charge on the sulfur and an equal negative charge on the oxygen. These fundamentally related approaches support the conclusion that electron-dipole interactions in the exit channel of SO- photodetachment play an important role in shaping the PADs. While a similar conclusion was previously reached for photodetachment from σ orbitals of CN- (Hart, Lyle, Spellberg, Krylov, Mabbs, J. Phys. Chem. Lett., 2021, 12, 10086-10092), the present work includes the first extension of the dipole-field model to detachment from π* orbitals.
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Affiliation(s)
- Beverly Ru
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, USA.
| | - C Annie Hart
- Department of Chemistry, Washington University, Saint Louis, MO 63130, USA
| | - Richard Mabbs
- Department of Chemistry, Washington University, Saint Louis, MO 63130, USA
| | - Samer Gozem
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, USA
| | - Anna I Krylov
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Andrei Sanov
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, USA.
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Dowek D, Decleva P. Trends in angle-resolved molecular photoelectron spectroscopy. Phys Chem Chem Phys 2022; 24:24614-24654. [DOI: 10.1039/d2cp02725a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In this perspective article, main trends of angle-resolved molecular photoelectron spectroscopy in the laboratory up to the molecular frame, in different regimes of light-matter interactions, are highlighted with emphasis on foundations and most recent applications.
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Affiliation(s)
- Danielle Dowek
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d’Orsay, 91405 Orsay, France
| | - Piero Decleva
- CNR IOM and Dipartimento DSCF, Università di Trieste, Trieste, Italy
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Anstöter CS, Verlet JRR. Modeling the Photoelectron Angular Distributions of Molecular Anions: Roles of the Basis Set, Orbital Choice, and Geometry. J Phys Chem A 2021; 125:4888-4895. [PMID: 34042462 DOI: 10.1021/acs.jpca.1c03379] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A study investigating the effect of the basis set, orbital choice, and geometry on the modeling of photoelectron angular distributions (PADs) of molecular anions is presented. Experimental and modeled PADs for a number of molecular anions, including both closed- and open-shell systems, are considered. Guidelines are suggested for chemists who wish to design calculations to capture the correct chemical physics of the anisotropy of photodetachment, while balancing the computational cost associated with larger molecular anions.
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Affiliation(s)
- Cate S Anstöter
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Jan R R Verlet
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
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