Dr. Yang Ding [HPSTAR, China & Argonne National Lab, USA]
Title: Pressure Tuned Insulator-Metal Transition in Mott systems
Time: 10:00 - 11:00 AM, Friday, October 16, 2015
Place: Conference room 201, HPSTAR (Shanghai)
Abstract:
Insulator-Metal transition is a fundamental topic in solid-state physics, but the underlying mechanism often remains unclear especially for Mott systems. Electron correlation effects can open up a gap in a partially filled band, giving rise to a Mott insulator. Its transition to a metal could be driven by either bandwidth control (BC) or filling control (FC). Recently, we have applied synchrotron x-ray spectroscopic methods (such as XAS, XRS, and RIXS) to study insulator-metal transition using pressure as a tuning parameter (BC) in four materials: a correlated metal V2O3, 3d Mott insulators PbCrO3 and SmNiO3, as well as a 5d spin-orbit induced Mott insulator Sr3Ir2O7. Our results demonstrate that while pressure can be a clean, effective, and theoretically transparent method to change the ratio of electron interaction over bandwidth U/W, its effects are still complicated owing to the interplay of charge, orbital, spin, and lattice degrees of freedom in Mott systems.
Biography of the Speaker:
Dr. Yang Ding joined Center for High Pressure Science &Technology Advanced Research (HPSTAR) as a staff scientist in June 2015. He was a staff scientist in the X-Ray Science Division at Argonne National Laboratory from 2011-2015, and a Research Scientist at Geophysical Laboratory of Carnegie Institution of Washington from 2005-2011. He received his Ph.D. from the Johns Hopkins University in 2002.
His research mainly concerns high-pressure condensed matter physics. His current interest focuses on studying emergent phenomena such as superconductivity, magnetism, and phase transitions in electron strongly correlated materials at high pressure by using novel synchrotron methods (i.e. resonant inelastic x-ray scattering, resonant x-ray emission, inelastic x-ray scattering, magnetic x-ray circular dichroism, x-ray absorption).