Interfacial Energy and Charge Transfer Dynamics

Interfacial electronic dynamics are at the heart of many emerging solar light harvesting systems, ranging from the production of solar fuels to novel approaches to photovoltaics. In this thrust, we provide a deeper understanding of the atomic-level details of ultrafast energy and charge transfer dynamics in interfacial systems using Time-resolved X-ray Photoemission Spectroscopy (TRXPS) and Time-resolved X-ray Absorption Spectroscopy (TRXAS). Experiments are performed at X-ray Free Electron Lasers and Synchrotron Light Sources, such as LCLS, FLASH, and ALS. Go here for further details.

Molecular Dynamics by Transient Inner-Shell Absorption Spectroscopy

Chemistry is enabled by the correlated dance of electrons and atoms, leading to the rearrangement of molecular structures, including the separation of existing and the formation of new inter-atomic bonds. Monitoring and understanding these fundamental steps of chemistry on their natural, ultrafast timescales is the focus of the transient inner-shell absorption spectroscopy thrust. Using femtosecond time-resolved core-to-valence XUV and X-ray transient absorption spectroscopy (TXA), we follow chemical transformations from the unique vantage points of specific reporter atoms. Go here for further details.

Molecular Dynamics by Ultrafast Electron Diffraction

Imagine how much easier it would be to understand chemistry if one could take snapshots of molecules with atomic resolution while they undergo chemical transformations. This is exactly what we are aiming for in the latest addition to our scientific portfolio. Using the Ultrafast Electron Diffraction (UED) facility at SLAC National Accelerator Laboratory, we study light-induced unimolecular reaction dynamics by illuminating the molecules with intense, femtosecond duration electron pulses. Go here for further details.

Dynamics in Helium Nanodroplets

Exploring the boundaries, commonalities, and distinct differences between the worlds of classical physics and quantum mechanics has led to some of the most fascinating revelations of modern science. In this activity, we explore the transition regions between the atomic and the macroscopic world and between classical and quantum physics. We use superfluid and normal fluid helium nanodroplets as unique testbeds for our understanding of the collective behavior of up to tens of billions of atoms, covering many orders of magnitude of individual atom and collective excitation. Employing ultrafast photoelectron and ion imaging spectroscopy with tabletop XUV light sources, as well as ultrafast coherent diffractive imaging and spectroscopy with X-ray Free Electron Lasers, such as LCLS and European XFEL, we gain a deeper understanding of dynamics in ground state, excited state, and highly ionized atomic clusters. We investigate phenomena ranging from the emergence of quantum vortices in rotating superfluid droplets, to the formation and relaxation of light induced nanoplasmas. Go here for further details.