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 Comment in Physical Review Letters examines a recent report of helicity-dependent charge-density-wave dynamics in 1T-TiSe₂. Using MeV ultrafast electron diffraction with a near-collinear pump-probe geometry and carefully characterized circular pump polarization, we find no measurable circular dichroism in the transient CDW response for either 800 nm or 10.6 µm excitation. Our results suggest that the previously reported effect may be complicated by grazing-incidence excitation, which substantially alters the polarization state inside the sample. This work highlights the need for careful control of optical geometry and polarization when probing chiral order in quantum materials.
Measurements were done at the MeV-UED user facility at SLAC in collaboration with the groups of Alfred Zong (Stanford) and Giulio Cerullo (Politecnico Milan).
Link to the open access publication: https://journals.aps.org/prl/abstract/10.1103/p5d8-548h
In our most recent work led by Bailey we report on solid-state high-harmonic generation spectroscopy (sHHG) inside a diamond anvil cell (DAC), opening an all-optical route to probe electronic structure under extreme pressure. Using MoS2 as a model system, we tracked how pressure reshapes the material’s electronic structure and uncovered an isostructural electronic transition near 15 GPa, marked by a sharp suppression of harmonic emission and a pronounced rotation of the polarization anisotropy. Supported by first-principles calculations performed by the Qiu group at Yale, the work shows that these signatures arise from a crossover of the lowest direct bandgap from the K-point to the Γ-point and from interference between competing excitation pathways in momentum space. These results establish solid-state high-harmonic generation as a sensitive new spectroscopic tool for studying pressure-tuned quantum materials in regimes that have been difficult to access experimentally.
Original publication available open access at Science Advances:
Shaneil won the outstanding GSI award for his instruction as head-GSI in the Physical Chemistry Laboratory (CHEM125). Congratulations!
