Bulletin of the American Physical Society
54th Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics
Volume 68, Number 7
Monday–Friday, June 5–9, 2023; Spokane, Washington
Session S11: V: Ultrafast PhenomenaVirtual Only
|
Hide Abstracts |
Chair: Carlos Marante Valdes, University of Central Florida Room: Virtual Platform |
Thursday, June 8, 2023 10:30AM - 10:42AM |
S11.00001: Experimentally resolving and decomposing the transfer of charge through a molecule on a single-femtosecond timescale Danylo T Matselyukh, Florian Rott, Thomas Schnappinger, Pengju Zhang, Zheng Li, Regina de Vivie-Riedle, Hans Jakob Wörner The rate limiting steps of charge-transfer (CT) reactions have been well understood for decades thanks to Markus theory, however, the motion of the electrons that is responsible for the CT is not considered separately. Using XUV Attosecond Transient Absorption Spectroscopy we have captured the sub-femtosecond electronic dynamics of CT in CF3I+ which we find to be mediated by a conical intersection (CoIn). The CT manifests itself as a drop in the transient absorption at one photon energy and a rise at another. With the help of state-of-the art calculations of the iodine N4,5 absorption spectrum and in-situ mass spectrometry, we are able to identify the two electronic states involved in the CT process as the B 2A2 fluorine-hole state and the E 2A1 iodine-hole state. |
Thursday, June 8, 2023 10:42AM - 10:54AM |
S11.00002: Zeptosecond and sub-mrad control of quantum equivalent non-local XUV pulses Carlos Trallero A Trallero, Geoffrey Harrison, Tobias Saule, Esteban Goetz, George N Gibson, Anh-Thu Le Through the application of intertwined wavefronts to an intense femtosecond pulse we can create two XUV pulses that are separated in space and yet have a phase jitter of 0.1mrad or 6zs at 80nm center wavelength. High harmonic generation creates XUV pulses between the 7th and the 17th harmonic of the fundamental 800nm . We perform single- and two-photon interferometric experiments to show that each photon carries the full high harmonic spectrum. This was established by collapsing the wavefunction of a photon and easuring spectrally and spatially the second. The presence of spatial interference in this case, shows that while highly coherent, the two photons are not entangled. The delay between the pulses can be controlled with a resolution of 100zs. We discuss applications to molecular dynamics spectroscopy. |
Thursday, June 8, 2023 10:54AM - 11:06AM |
S11.00003: Generate short isolated attosecond pulses with waveform-shaped infrared laser by controlling a trajectory parameter Dian Peng, Jean Marcel Ngoko Djiokap Reaching ever shorter duration of isolated attosecond pulses (IAPs) is an ongoing mission in attosecond science. Widely usage of long-wavelength driving lasers has greatly broadened bandwidths for generating IAPs. We propose a strategy to further exploit the ability of a long-wavelength laser in producing short IAPs. We discovered a scaling relationship between IAP duration and a trajectory parameter that is associated with the classical cutoff trajectory of high-order harmonic generation (HHG) in gases. This trajectory parameter can then be used to generate short IAPs by shaping laser waveform. We demonstrate the effectiveness of our methods with numerical calculations of HHG from Ne. Our results show that using an additional short-wavelength (e.g., deep ultraviolet) laser pulse together with the infrared is an effective way to shorten IAP duration (from 76 to 47 as in our example), for which insightful physical explanations are provided. |
Thursday, June 8, 2023 11:06AM - 11:18AM |
S11.00004: Doping effects in high-harmonic generation from correlated systems Thomas Hansen, Lars B Madsen Using the one-dimensional Hubbard-model, doping effects in high-harmonic generation (HHG) from correlated materials were studied. High Tc-superconducting cuprates often fall into this category of materials. The special and commonly used case of half-filling leads to Mott insulating behavior for strongly correlated materials [1-2]. For relatively small Hubbard U, i.e., small electron-electron correlation, doping had little to no effect on the dynamics nor the HHG spectra. For large U, the dynamics and spectra are heavily influenced by the degree of doping. These findings are explained through the quasiparticle-based doublon-holon picture. Doublons are doubly occupied lattice sites, and holons are unoccupied lattice sites. The dynamics are separated into two types: doublon and holon movement, and doublon-holon pair creation and annihilation. Doping results in all configurations containing doublons or holons. Those quasiparticles can move at no extra cost in energy regardless of the correlation level. This motion at no energy cost increases the high-harmonic gain for low- and medium-harmonic orders. Finally, a decrease in the probability for antiferromagnetic ordering with an increasing doping rate, in the high U limit, is discussed and used to explain a drop in the high-order harmonics relative to half-filling [3]. |
Thursday, June 8, 2023 11:18AM - 11:30AM |
S11.00005: Exploring damage reduction and scattering cross section enhancement in attosecond X-ray imaging of neon near the K-edge Anatoli Ulmer, Stephan Kuschel, Bruno Langbehn, Linos Hecht, Simon Dold, Lara Rönnebeck, Taran Driver, Joseph Duris, Andrei Kamalov, Xiang Li, Ming-Fu Lin, Razib Obaid, Adam M Summers, Peter Walter, James Cryan, Rupp Daniela, Agostino Marinelli, Tais Gorkhover, on behalf of the LV17 collaboration Ultrafast X-ray coherent diffraction imaging combines nanometer spatial resolution with few to sub-femtosecond temporal precision. In a diffraction before diffraction scheme, ultrabright FEL pulses are scattered by the sample before it's ionic structure is substantially modified. It has been suggested in theoretical studies that the induced sample damage can be reduced if the pulses are much shorter than the relaxation processes, such as Auger decay [Rohringer et al., Phys. Rev. A 77, 053404]. |
Thursday, June 8, 2023 11:30AM - 11:42AM |
S11.00006: Probing dynamics of high harmonic generation in liquids Angana Mondal, Ofer Neufeld, Zhong Yin, Zahra Nourbakhsh, Vit Svoboda, Angel Rubio, Nicolas Tancogne-Dejean, Hans Jakob Woerner High-harmonic spectroscopy (HHS) is a successful in-situ attosecond probe of electron dynamics in gases and solids [1,2,3]. However, HHS in liquids, has so far been limited by the lack of an intuitive understanding of the high harmonic generation (HHG) process. Studying HHG over a wide range of wavelengths (λ), intensities and pulse durations, we show that the cut-off (Ec) is a characteristic liquid dependent property, independent of λ beyond a threshold intensity [4,5]. We explain these observations within an intuitive semi-classical model based on electron trajectories that are limited by scattering to a characteristic length, which is connected to the electron mean-free path (MFP). This is validated with ab initio time-dependent density-functional-theory calculations. The model is further verified experimentally through the systematic control Ec by the variation of liquid density resulting in a change in the effective MFP [4]. Our work establishes the possibility of resolving sub-femtosecond electron dynamics in a bio-chemically relevant liquid environment. |
Thursday, June 8, 2023 11:42AM - 11:54AM |
S11.00007: Strong-field-driven solids monitored by attosecond transient absorption spectroscopy Stefano M Cavaletto, Lars Bojer Madsen Strong-field dynamics in solids have recently received significant attention in high-order harmonic generation and for the ultrafast manipulation of the conduction properties of solids with light. Attosecond transient absorption spectroscopy (ATAS) has been used to monitor these ultrafast dynamics, by scanning the delay between the strong optical pump and an additional XUV or x-ray probe. Here, we employ time-dependent density functional theory to simulate strong-field dynamics in solids probed by XUV pulses. We identify delay-dependent features in the ATAS signal and show how these can be used to access the underlying strong-field dynamics. |
Thursday, June 8, 2023 11:54AM - 12:06PM |
S11.00008: Spin-Orbit Coupling and Relativistic Correction in Strong-Field Ionization Andrew S Maxwell, Lars Bojer Madsen Spin is commonly ignored in strong-field physics. This is due to the fact that it has only been shown to play a role through spin-orbit coupling for states with high orbital-angular momentum, and with an elliptically polarized fields. Furthermore, in experiment, spin-resolved measurements have only fairly recently become possible. Thus, theoretical models treat spin only through coupling to initial states and generally neglect the spin dynamics. However, the trend for longer wavelengths, e.g. in imaging processes such as laser induced electron diffraction (LIED), means that spin dynamics may play an important role for linear fields, through high energy rescattering. |
Thursday, June 8, 2023 12:06PM - 12:18PM |
S11.00009: Time-resolved study of H3+ formation via roaming neutral H2 in acetonitrile Debadarshini Mishra, Aaron C LaForge, Lauren M Gorman, Sergio Díaz-Tendero, Fernando Martín, Nora Berrah Roaming reactions have garnered significant interest in recent years since they defy the conventional reactions that follow minimum energy pathways. Instead, such reactions involve flat regions of the potential energy surface where molecular fragments remain weakly bound and participate in long-range interactions mediated by relatively weak forces. We will present the time-resolved study of H3+ ions formed due to roaming H2 neutrals in acetonitrile, using coincident Coulomb explosion imaging in combination with pump-probe spectroscopy. We demonstrate that by reconstructing dynamical information of the ‘invisible’ neutral roamers, it is possible to directly track and observe experimental signatures of roaming. Along with state-of-the art quantum chemistry calculations, our measurements and analysis provide a robust, kinematically complete picture of roaming mechanism in acetonitrile. |
Thursday, June 8, 2023 12:18PM - 12:30PM |
S11.00010: Diatomic molecular vibrations in a strong infrared laser field: an analytic treatment of the laser-dressed Morse potential Szabolcs Hack, Attila Czirják, Gábor Paragi, Péter Földi, Imre F Barna, Sándor Varró Diatomic molecules driven by strong laser pulses show a rich variety of fundamentally important processes, depending on how the laser pulse parameters are related to the diatomic's properties. Although the theoretical framework for molecules interacting with laser fields is well established, analytic methods are rare and approximate in the strong-field domain, while most of the numerical methods have heavily increasing cost for infra-red (IR) wavelength [1,2]. |
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