Bulletin of the American Physical Society
51st Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics
Volume 65, Number 4
Monday–Friday, June 1–5, 2020; Portland, Oregon
Session C04: Imaging of Ultrafast Molecular DynamicsInvited Live
|
Hide Abstracts |
Chair: Linda Young, University of Chicago and Argonne National Laboratory Room: D137-138 |
Tuesday, June 2, 2020 10:30AM - 11:00AM Live |
C04.00001: Imaging dynamics in complex molecules with ultrafast electron diffraction Invited Speaker: Martin Centurion The conversion of light into chemical and mechanical energy is the driving mechanism in many processes in nature, such as photosynthesis, vision, DNA photodamage and solar energy harvesting and storage. This energy conversion takes place when, after absorbing a photon, the molecule undergoes a rearrangement of the atomic positions and bonds. Observing these dynamics requires simultaneously reaching atomic (sub-Angstrom) spatial resolution and temporal resolution on the order of 100 fs. Recent advances in ultrafast electron diffraction (UED), in particular the implementation of relativistic electron sources for UED experiments with gas phase samples, now allow us to observe structural dynamics in isolated molecules. UED experiments have succeeded in progressing from first demonstrations in diatomic molecules to systems of increasing complexity. We will discuss a few exemplary reactions were we have imaged bond breaking, the motion of nuclear wavepackets and coherent vibrations that persist after the molecule returns to the electronic ground state. [Preview Abstract] |
Tuesday, June 2, 2020 11:00AM - 11:30AM Live |
C04.00002: Imaging Molecular Dynamics of Non-Periodic Systems with Ultrafast X-ray Scattering Invited Speaker: Adi Natan Ultrafast x-ray scattering is an emerging tool to probe photoexcited molecular dynamics at the angstrom and femtosecond scale. This talk will discuss the different approaches used to leverage the information of the scattering signal. We will demonstrate how signal anisotropy can be used to reveal and disentangle weak to strong field dynamics of excited systems, both in the gas-phase and in solution. We will show how using spectral and wavelet-based analysis approaches allow to track non-periodic and complex motions such as temporal accelerations de-novo. These approaches harness both the temporal and spatial resolutions of the measurement to resolve in time and momentum weak signals below what is currently attainable using traditional methods and open the way to obtain track motions in more complex systems. We will discuss the limits of motion detection and the impact that higher photon energies, shorter pulses and high-repetition rate sources such as LCLS-II will have on ultrafast x-ray scattering of non-periodic systems. [Preview Abstract] |
Tuesday, June 2, 2020 11:30AM - 12:00PM Live |
C04.00003: Imaging ultrafast molecular transformations with laser-induced electron diffraction Invited Speaker: Cosmin Blaga Diffraction-based ultrafast imaging techniques are experimental tools developed to follow nuclear motions with atomic-scale spatio-temporal resolutions during molecular transformations. This talk Introduces the key concepts of laser-induced electron diffraction (LIED), a table-top modern adaptation of conventional gas-phase electron diffraction where the rescattering mechanism present during strong-field ionization takes the role of the traditional external electron bean. An overview of recent successful implementations of LIED from small molecules to fullerenes will be presented, discussing various implementations of the method, its advantages but also its challenges. Finally, the talk will address the future of LIED in conjunction with the latest developments in intense, femtosecond laser technologies and electron detection schemes. [Preview Abstract] |
Tuesday, June 2, 2020 12:00PM - 12:30PM Live |
C04.00004: Attosecond pump-probe spectroscopy of molecular electron dynamics Invited Speaker: Fernando Martin Attosecond and few femtosecond light pulses allow one to probe the inner workings of atoms, molecules and solids on the timescale of the electronic motion. In molecules, sudden ionization by such pulses is followed by charge redistribution on a time scale ranging from a few-femtoseconds down to hundreds attoseconds, and usually leads to fragmentation of the remaining molecular cation. Such complex dynamics arises from the coherent superposition of electronic states populated by the broadband attosecond pulse and from rearrangements in the electronic structure of the molecular cation due to electron correlation. To investigate these ultrafast processes, attosecond pump-probe spectroscopy has been shown to be a very valuable tool. In this talk I will present the results of recent attosecond pump-probe simulations in which several molecules, from hydrogen to the amino acid tryptophan, are ionized with a single or a train of attosecond pulses and are subsequently probed by an infrared or an XUV pulse (see [1] for a recent review on the subject). [1] M. Nisoli, P. Decleva, F. Calegari, A. Palacios, and F. Mart\'{\i}n, Chem. Rev. 117, 10760 (2017). [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700