CAREER: Non-equilibrium Dynamics in Cuprate Superconductors Studied by Coherent Ultrafast Spectroscopy and Ultrafast Electron Diffraction

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Non-Technical abstract:This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This CAREER award funds a project to understand the mechanism of superconductivity in cuprates by studying dynamics of ultrafast events taking place at the atomic scale. Superconductivity is the total loss of electrical resistance below a critical temperature. Currently, copper oxygen based cuprate superconductors have the highest known transition temperatures. Even in these materials, the transition temperatures are far below the room temperature which hinders potential applications and the mechanism of superconductivity is still not known. This project will use ultrashort laser pulses to make atomic scale ?movies? of dynamics of electrons and the lattice structure with both spatial and temporal resolutions. Information obtained from these measurements will help to understand the complex interactions leading to high temperature superconductivity in cuprates which may in turn enable predicting superconductors with higher transition temperatures. A strong emphasis will be placed on developing education and outreach programs integrated to the research component of this project. The education component of this project will enable training of graduate and undergraduate students capable of applying these techniques to different fields. A graduate level course dedicated to the application of ultrafast techniques to condensed matter physics will be developed and its material will be made freely available through the internet. The outreach part of this program will contribute improving the quality of K-12 math and science education especially in socio-economically impacted regions. This will be achieved by working closely with math and science oriented charter schools and education research institutions. Technical abstract:This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The goal of this Early Faculty CAREER project is to understand the mechanism of superconductivity in cuprates by studying the dynamics of their low energy excitations and phase transitions. After photoexcitation by ultrashort light pulses, the recovery of the resulting non-equilibrium state will be probed in both space and time using either light or electron pulses providing information about evolution of electronic and structural degrees of freedoms. In the high excitation density limit, non-equilibrium phase transitions will be induced into states that can be either thermally accessible or completely novel. Studying the dynamics of these phase changes will provide crucial information about the competing states of these materials and yield clues about their complex phase diagram. By studying the weak excitation limit, important insights will be obtained into the nature of couplings between different internal degrees of freedoms. A strong emphasis will be placed on developing education and outreach programs integrated to the research component of this project. The education component of this project will enable training of graduate and undergraduate students capable of applying these techniques to different fields. A graduate level course dedicated to the application of ultrafast techniques to condensed matter physics will be developed and its material will be made freely available through the internet. The outreach part of this program will contribute improving the quality of K-12 math and science education especially in socio-economically impacted regions. This will be achieved by working closely with math and science oriented charter schools and education research institutions.