Welcome to the session for Atomic, Molecular and Optical (AMO) physics during the Swedish Physics Days in Stockholm 2023! The AMO section of the Swedish Physical Society will arrange a scientific program for the AMO session that highlights the breadth of ongoing AMO research in Sweden with invited speakers from Lund, Göteborg, Stockholm, Uppsala and Umeå. In addition, a number of contributed...
$\textbf{Attosecond time-resolved experiments at a seeded free electron laser}$
Praveen Kumar Maroju$^{1,2}$ , Michele Di Fraia$^{3}$, Oksana Plekan$^{3}$, Matteo Bonanomi$^{4,5}$, Barbara Merzuk$^{1}$, David Busto$^{1,2}$, Ioannis Makos$^{1}$, Marvin Schmoll$^{1}$, Ronak Shah$^{1}$, Primož Rebernik Ribič$^{3}$, Luca Giannessi$^{3,6}$, Giovanni De Ninno$^{3,7}$, Carlo Spezzani$^{3,7}$,...
In multi-electron systems such as atoms and molecules, the electron-electron interaction poses a major challenge for the accurate theoretical description of atomic structure and dynamics, requiring sophisticated numerical approaches. These theoretical models are then also used to provide required information for experimental analysis such as for nuclear square charge radii determinations from...
New insight into mechanisms that can help to make propulsion and power systems “greener” and more sustainable cannot be simulated or known a priori, it needs to be developed through the rigorous testing and quantification. Ultrafast laser diagnostics has a tremendous potential to provide precise scalar determination at these harsh test environments, where often steep gradients in temperature...
Coherent anti-Stokes Raman Spectroscopy (CARS) being one of the important measurement techniques in reactive flows, we present a novel method to improve its diagnostic ability using quantum control. This is achieved by carefully engineering the interference of two confined quantum wavepackets, by the implementation of 2- beam hybrid fs/ns rotational CARS along with a second (control) pulse...
Photonics platforms provide promising advantages for many applications in the field of quantum information processing and sensing. Bulk and free-space optical systems exhibit issues in terms of scalability, cost, reproducibility, and reconfigurability. A more intriguing platform is therefore given by integrated photonics circuits, which allow the miniaturization, reproducibility, and...
Molecular line lists for gases at high temperatures are crucial in fields ranging from combustion to astrophysics. However, due to the lack of experimental data, some of the energy levels that constitute the lists are inaccurate or even missing, and their theoretical models need validation. Addressing these gaps is especially important for methane, a key greenhouse gas and one of the...
We present mutual neutralization studies of $^{1,2}$H$^-$ with Li$^+$, O$^+$, N$^+$ and C$^+$ at DESIREE. The systems are of astrophysical interest and the collisions take place at sub-electronvolt energies which are typical collision energies in cold stellar photospheres. The most prominent finding is a strong isotope effect on the branching fraction into Li(3s), which constitutes one of the...
The cosmic origin of the neutron-capture elements beyond iron in the periodic table has long been a puzzle. In 2017, the observation of GW170817 provided the first-ever observational clue that kilonovae could be the primary source of these heavy elements. However, spectral elemental analysis of kilonovae is hindered by the lack of complete and accurate atomic data for neutron-capture elements...
4d and 5d metal carbonyls are widely recognized for their photocatalytic C-H bond activation capabilities. UV excitation of these complexes leads to CO dissociation and the formation of a reactive metal center, which rapidly binds alkane C-H groups from solution and ultimately breaks the C-H bond. The reactivity of 3d metal carbonyls following photoinduced CO dissociation, however, is often...
Fullerenes are the largest molecules identified thus far in the interstellar medium and have been the focus on countless studies since their discovery nearly four decades ago. [1] They do, however, still hold many secrets. At DESIREE [2], the Double ElectroStatic Ion Ring ExpEriment, a national infrastructure for ion physics research located at Stockholm University, we have recently performed...
The interaction of atoms with attosecond ($10^{-18}$ s) light pulses has renewed interest in studying photoionization dynamics. The ionized electrons exhibit a wave-like behaviour that is commonly used to retrieve the temporal dynamics of the process using optical cross-correlation techniques between light pulses. In this work, we study the photoionization dynamics of helium in a new regime...
It has been widely recognized in the scientific community that scarce elements such as ruthenium are not ideal for sustainable technology. During the past 10 years, progress has been made in exploring first-row transition metals as replacements for scarce metals in many solar cell and photocatalysis applications.[1] Iron analogues to well-performing ruthenium-complexes were early found to not...
Disulfur, S2, is a reactive intermediate known to be important in the atmosphere of Jovian planets. Whereas the single ionization valence photoelectron spectrum of S2 is known from the early work of Dyke and coworkers, revealing its double ionization electron spectrum remained a challenge for a long time. Using time-of-flight multiple electron and ion coincidence techniques, in combination...
Raman spectroscopy can be used to detect, identify, and characterize microbial organisms. In clinical settings such as hospitals, there is a need for methods to verify the sterilization of environments and equipment from pathogenic microbes such as bacteria. Of particular interest is the sterilization of so-called spore-forming bacteria since these can enter a zombie-like state when exposed to...
Conical intersections (CIs) play a vital role in processes such as the event of vision and DNA damage from sunlight. A CI appears in a molecule when electronic and nuclear motions are strongly coupled, and it acts as a funnel that guides a molecule from one electronic state to another. Substantial efforts have been made toward understanding such non-adiabatic phenomena. X-ray Raman techniques...
In mutual neutralisation, two oppositley charged ions collide, an electron is tranfered and the colliding pair ends up in neutral fragments. In the Born-Oppenheimer approach the electronic structure of the molecule is solved for in an initial step, and the nuclear motion is solved for in a second step giving relevant scattering information such as cross section, differential cross section and...
Attosecond transient absorption spectroscopy (ATAS) is used to study electron dynamics with the aim of unravelling ultra-fast phenomena in atoms and molecules. There have been many investigations on ATAS between bound states [1], but few works has focused on the coupling of a prepared bound wave packet to both bound and continuum states [2]. A recent experimental investigation of the physical...
Transition metal carbonyls have played a significant role in the photochemistry of organometallic complexes. The ultraviolet excitation of these complexes often results in the loss of one or more carbonyls[1] that create short-lived reactive intermediates capable of interacting with the available solvent.[2] Vibrational cooling timescales and the complex free energy surface of the electronic...
Electron particle accelerators are the base for generation of intense X-rays. A Free Electron Laser (FEL) based on such an accelerator is able to control the process to give the X-rays laser-like properties. A FEL can provide coherent X-rays at extreme powers (GW to TW) and in very short pulses (femto-seconds to atto-seconds).
This poster will present an overview of our FEL related research....
Negative ions are interesting quantum systems due to the nature of the force that binds the extra electron. Since the nucleus effectively screens the Coulomb attraction, the additional electron is bound by a dipole moment induced by electron-electron interactions. As a result, typical spectroscopic methods can not be applied and the only quantity that can be probed with high precision is the...
The double electrostatic ion-beam storage ring is a Swedish national research infrastructure offering beam time to users interested in studying ions of atoms, molecules and clusters. The facility is cryogenic, which results in very long ion-beam storage times and the ions are subject to interaction with a number of different laser sources and, as there are in fact two ion-storage rings in the...
The photolysis of aryl azides is widely used to produce highly reactive aryl nitrenes, an active intermediate in organic and inorganic synthesis. Phenyl azide (Ph-N$_3$) is considered a model system for a class of aryl azides. The photoproducts of phenyl azide have applications in various fields, e.g., photoaffinity labeling of enzymes, and preparation of electrically conducting...
Abstract: We demonstrate experimentally a new quantum state tomography protocol for photoelectrons. The measured reduced density matrix, originating from different noble gases, shows that the photoelectron purity decreases due to ion–electron entanglement induced by spin–orbit interaction. Opening up the possibility for directly studying quantum properties of photoelectrons on a...
When an atom is driven by a laser field with a photon energy that is nearly resonant with an atomic transition, it can undergo periodic population transfers between the ground and excited state, known as Rabi oscillations [1,2]. The aim of this work is to study photoionization from atoms for parameters accessible to a free-electron laser (FEL) [3]. Using time dependent perturbation theory to...
In most atomic systems, single ionisation- channel continua are the exception, rather than the norm. When multiple ionisation channels are open, the purity of the state density operator can provide information on the electron–Parent Ion (PI) entanglement. Although this informa- tion may not be extracted using only an XUV pump, it can be obtained with the addition of a probe pulse. This is the...
Attosecond physics aims to unravel the electron motion and coherence in atoms and molecules. Major contributions to this field are the real-time observations of the motion of electrons in ions and atoms through attosecond transient absorption spectroscopy (ATAS). Despite the great success of ATAS, all studies have so far been based on non-relativistic ATAS theory. Seeking a compromise between...
Synopsis
We have performed experimental and theoretical studies of knockout processes with carbonaceous molecules, and draw conclusions about the lifetimes of their decay products and their possible survival in astro- physical environments.
Abstract
The presence of polycyclic aromatic hydrocarbons (PAHs) in the interstellar medium was proposed in the 1980’s [1][2] and later...
