Detail:
Abstract: Strongly correlated materials possess many remarkable properties, such as high-Tc superconductivity in cuprates and colossal magnetoresistance in doped manganites, arising from the complex interplay between spin, charge, orbital and lattice degrees of freedom. Electron liquid crystal (ELC) phases provide unique descriptions to characterize the electronic structures and elucidate the underlying physics in correlated materials from symmetry perspective. Although ELC phases have been proposed to play a key role in interpreting the structure-property relationship in a wide range of correlated materials, the nature of the transition between such phases has received little experimental attention. La1/3Ca2/3MnO3 is an excellent candidate to study ELC phases and infer the roles of various degrees of freedom in material’s properties from a wealth of emergent phenomena in this material including the electronic inhomogeneities at the nanoscale. Using transmission electron microscopic tools with recently developed techniques, we explored ELC phase transitions in La1/3Ca2/3MnO3 and obtained direct observations of the transitions via the formation of defects and electronic phase separation. In particular, we found that charge inhomogeneity is accounted for the mechanism of electronic smectic-nematic phase transition, while the electronic nematic to isotropic phase transition is driven by charge inhomogeneity and strain effect in this material. At the end of the talk, some special capabilities at Brookhaven National Laboratory, such as ultrafast electron diffraction, will be introduced. Brief resume of Jing Tao: Dr. Jing Tao received her PhD from University of Illinois at Urbana-Champaign in 2005. After a few years of postdoctoral research at Oak Ridge National Laboratory, she moved to Condensed Matter Physics & Materials Science Department at Brookhaven National Laboratory (BNL) in 2007. Dr. Tao is currently a physicist at BNL and focuses on the electronic structural characterization of strongly correlated materials using transmission electron microscopic techniques. She has published more than 50 papers in peer-reviewed journals, including Nature, Science and PRL.
