We have now observed three distinct charge density waves in the nematic superconductor, Ba1−xSrxNi2As2 (BSNA). This pnictide material has the same structure as the 122-phase FeAs superconductors, but contains Ni instead of Fe. Paglione’s group at the University of Maryland recently observed a sixfold enhancement of superconductivity in this material due to nematic fluctuations near […]
We were recently awarded a $12.6M Energy Frontier Research Center by the U.S. Department of Energy. With our partner, SLAC National Accelerator Laboratory, we will pioneer several new quantum sensing techniques for studying elementary phenomena in quantum materials. These will include a scanning qubit microscope, a time-of-flight instrument for detecting Einstein-Podolsky-Rosen pairs of electrons, and […]
We just finished a study demonstrating a way to use time-resolved RIXS to measure the collective exctiations of quantum materials, in this instance CDW-ordered La2-xBaxCuO4 (LBCO). The idea is to weakly perturb the system with a pump pulse and then measure the time evolution of the order parameter, which encodes the collective excitations of the […]
These images were taken at beamline ID-6 at the Advanced Photon Source (credit: Ali Husain).
Our paper on density fluctuations in Bi2Sr2CaCu2O8+x appeared in the Proceedings of the National Academy of Sciences. This study shows that, unlike conventional metals, this so-called “strange metal” does not exhibit propagating plasmons. Instead, it shows a continuum of fluctuations exhibiting “local scale invariance”–a phase in which time and space axes become decoupled. The origin […]
After several months of HVAC renovations the M-EELS instrument is back up and running. Looking forward to a blissful summer of experiments.
The M-EELS experiment is down for six weeks as the ESCO project to rebuild the HVAC system for the entire MRL building moves to our floor. The whole instrument is now encased in a giant plywood box to protect it from dust and mishaps. We hope to be recommissioning the instrument in the middle of March. […]
We just published a paper finally demonstrating that TiSe2 contains a Bose condensate of excitons. The experimental signature is a soft plasmon that falls to zero frequency at Tc. Bert Halperin and Maurice Rice nicknamed this phase “excitonium” in their 1968 Rev. Mod. Phys. paper to emphasize the physical picture of an exciton condensate as an electronic crystal. […]