Welcome to the
The Zuerch Lab at the University of California at Berkeley experimentally explores structural, carrier and spin dynamics in novel quantum materials, heterostructures and at material interfaces to answer current questions in materials science and physical chemistry. For this we pursue a multidisciplinary research program that combines the exquisite possibilities that ultrafast X-ray spectroscopy and nanoimaging offers and closely interface with material synthesis and theory groups. We employ state-of-the-art methods and develop novel nonlinear X-ray spectroscopies in our lab and at large-scale facilities. Specifically, we are interested in experimentally studying and controlling material properties on time scales down to the sub-femtosecond regime and on nanometer length scales to tackle challenging problems in quantum electronics, information storage and solar energy conversion.
Learn more about our research.
Latest news:
Our latest publication addresses a long-standing challenge in understanding the UV photochemistry of bromoform (CHBr₃), focusing on the elusive mechanisms driving the production of atomic and molecular bromine fragments. Using gas-phase ultrafast megaelectronvolt electron diffraction (MeV-UED) with femtosecond resolution, we directly capture the structural dynamics following 267 nm photon excitation. Our findings reveal that isomerization, specifically forming the iso-CHBr₃ (Br-CH-Br-Br) isomer, plays a substantial role alongside direct C–Br bond cleavage in the early stages of reaction. Remarkably, about 60% of the molecules undergo isomerization within the first few hundred femtoseconds. These results align well with ab initio molecular dynamics simulations and suggest a roaming mechanism, providing new insights into the competing pathways in bromoform photochemistry.
This work was led by the Gessner group (LBNL) in collaboration with the Centurion group (U Nebraska-Lincoln), our group and a number of colleagues from SLAC and UC Berkeley. First author Lars was a master student in the Zuerch Lab when we were still at the Fritz Haber Institute in Berlin and he is now jointly advised by Oliver Gessner and Michael.
The paper got published in the Journal of the American Chemical Society:
https://pubs.acs.org/doi/full/10.1021/jacs.4c07165
We are excited to share our latest preprint. Utilizing our unique cryogenic attosecond beamline, we identified distinct core-level signatures of CDW formation in time-resolved measurements that were undetectable in equilibrium photoemission and absorption measurements in the putative excitonic insulator TiSe2. We also observe excitonic correlations in the normal-state of the material above the transition temperature. These findings provide crucial insights into the mechanism of exciton condensation in this material, highlighting the interplay between short-range excitonic fluctuations and long-range order. Our work underscores the importance of attosecond spectroscopy in exploring both equilibrium phase diagrams and novel nonequilibrium states in strongly correlated materials.
Preprint available here: https://arxiv.org/abs/2407.00772
Our latest research explores into the controversial intermediate liquid phase of carbon, a topic debated for decades. Using time-resolved resonant inelastic X-ray scattering (RIXS) and X-ray emission spectroscopy (XES), we studied amorphous carbon and ultrananocrystalline diamond under laser irradiation. Our findings indicate no evidence of a liquid state, instead revealing crystalline properties even under extreme conditions. Differences in signal behavior are attributed to variations in sample thickness and incomplete melting. This study enhances our understanding of carbon’s behavior under high-energy conditions, with significant implications for material science.
The measurements were done at the PAL free-electron laser. This research was done in a larger collaboration led by Saykally and Schwartz.
Journal publication in the Journal of Physical Chemistry B here: https://pubs.acs.org/doi/full/10.1021/acs.jpcb.4c02862
