The Zuerch Lab at the University of California at Berkeley experimentally explores structural, carrier and spin dynamics in novel quantum materials, heterostructures and on surfaces and at 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.
We are excited to see our latest paper on “Coherent Phonons in Antimony: An Undergraduate Physical Chemistry Solid-State Ultrafast Laser Spectroscopy Experiment” published in the ACS Journal of Chemical Education. This paper in chemical education discusses in deep detail an ultrafast spectroscopy experiment that we developed for our undergraduate teaching laboratory at Berkeley. In the experiment, the students measure coherent phonons in antimony using the output of a femtosecond laser oscillator which they also characterize in the time domain. This lab experiment that is usually done by juniors and seniors in the Chemistry curriculum has since its inauguration become one of the favorite experiments that students in this course do. We hope it will spark excitement for research using ultrafast methods in their future careers.
This work was done in collaboration with Steve Leone and Anne Baranger.
Our open access paper is now published in the Journal of Chemical Education:
Topological defects play a key role in nonequilibrium phase transitions, ranging from birth of the early universe to quantum critical behavior of ultracold atoms. In solids, transient defects are known to generate a variety of hidden orders not accessible in equilibrium, but how defects are formed at the nanometer lengthscale and femtosecond timescale remains unknown. In this work, we discovered the sub-picosecond formation of 1D topological defects in a two-dimensional charge density wave using ultrafast electron diffraction. We discovered a dual-stage growth of 1D domain walls which takes place within 1 ps which is mediated by nonthermal lattice vibrations. This work constitutes the first visualization of topological defect formation process in the femtosecond timescale. Our work provides a framework for ultrafast engineering of topological defects based on selective excitation of collective modes, opening new avenues for dynamical control of nonequilibrium phases in correlated materials.
This work was done in collaboration with researchers from Shanghai Jiao Tong University, Brookhaven National Laboratory, ShanghaiTech University, University of Amsterdam and UCLA.
Pre-print available here:
Our group welcomes Prof. Craig Schwartz from the University of Nevada, Las Vegas. Craig is a long-term collaborator of our group on XUV and FEL science and will be visiting our group for the next year.