"Towards properties-on-demand in quantum materials"
Abstract: Quantum materials manifest fascinating phenomena ranging from superconductivity to metal-insulator transitions. Many of these materials exhibit colossal changes to external perturbations which includes electromagnetic excitation. This opens exciting possibilities for “on-demand” control of emergent properties using light. From equilibrium and non-equilibrium perspectives, such materials offer enormous possibilities for light-based discovery and control arising from the delicate interplay between interactions and dimensionality. Following a global overview of this topic, I will present vignettes highlighting the potential of light to explore quantum materials and nonequilibrium dynamics. The terahertz region of the electromagnetic spectrum (roughly 0.1 – 20 THz) is particularly fertile as this spans the appropriate time/energy scale in quantum materials. I will present examples ranging from “simple” to complex, with a focus on transition metal oxides. This includes coherent spin manipulation in antiferromagnets, insulator-to-metal transition dynamics, augmented superconductivity and, in a putative excitonic insulator, terahertz parametric amplification arising from coherent order parameter dynamics. Time permitting, I will briefly introduce cavity-controlled quantum materials which is an emerging area providing novel control knobs to manipulate complexity.
Bio: Richard Averitt received his PhD degree in Applied Physics from Rice University in 1998 for work on the synthesis and optical characterization of gold nanoshells. Following this, he was a Los Alamos National Laboratory Director’s Postdoctoral Fellow where his work focused on time resolved spectroscopy of correlated electron materials and metamaterials. In 2001, Richard became a member of the technical staff at Los Alamos, and in 2005 a member of the Center for Integrated Nanotechnologies co-located at Los Alamos and Sandia National Laboratories. In 2007, Richard joined Boston University as a faculty member in the Department of Physics and the Boston University Photonics Center. Since 2014, Richard has been with the Department of Physics at UC San Diego. Richard’s current research is primarily directed towards characterizing, creating, and controlling the optical and electronic properties of metamaterials, plasmonic materials, and quantum materials using ultrafast optical spectroscopy spanning from terahertz to visible frequencies. Richard is a fellow of Optica and the American Physical Society and currently serves as the Associate Dean for Graduate Education in the School of Physical Sciences at UCSD.
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