Ultrafast Carrier Dynamics in La1-xSrxMnO3/SrTiO3 Heterostructures

ORAL

Abstract

Transition metal oxide thin films and heterostructures have attracted interest of community due to manifestation of broken symmetry and dimensional confinement, which create new forms of coupling and consequently new functionality. An important challenge is to probe the excited states of these artificially structured materials. Ultrafast reflectivity measurements can be used to study the highly nonequilibrium exited states and observe subsequent dynamical behavior. We grew La1-xSrxMnO3/SrTiO3(001) heterostructures using different growth conditions, being able to control structural and compositional modulation near the interface, which profoundly changes electronic and magnetic properties of these thin films. Using ultrafast reflectivity measurements, we show novel excited-state relaxation dynamics and phonon oscillations in these heterostructures. The changes in these relaxations will be discussed relevant to the growth conditions. With specific growth condition, we observed the relaxations of electron-phonon coupling and phonon-phonon coupling with larger than expected lifetimes as well as the oscillations of two phonon modes. Furthermore, pump-power dependent reflectivity and lifetimes were also studied.

–

Presenters

  • Kun Zhao

    Department of Physics & Astronomy, Louisiana State University, Department of Physics and Astronomy, Louisiana State University, Baton Rouge

Authors

  • Kun Zhao

    Department of Physics & Astronomy, Louisiana State University, Department of Physics and Astronomy, Louisiana State University, Baton Rouge

  • Joel E Taylor

    Department of Physics & Astronomy, Louisiana State University, Department of Physics and Astronomy, Louisiana State University, Baton Rouge

  • Rami A Khoury

    Department of Chemistry, Louisiana State University

  • Mohammad Saghayezhian

    Department of Physics and Astronomy, Baton Rouge, Louisiana 70803, US, Louisiana State University, Louisiana State University, Department of Physics & Astronomy, Louisiana State University, Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Physics and astronomy, Louisiana State University

  • Louis H Haber

    Department of Chemistry, Louisiana State University, Department of Chemistry, Louisiana State University, Baton Rouge

  • Jiandi Zhang

    Department of Physics and Astronomy, Baton Rouge, Louisiana 70803, US, Louisiana State University, Louisiana State University, Department of Physics & Astronomy, Louisiana State University, Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Physics and astronomy, Louisiana State University

  • E Ward Plummer

    Louisiana State University, Department of Physics & Astronomy, Louisiana State University, Dept. of Physics and Astronomy, Louisiana State University, USA, Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Physics and astronomy, Louisiana State University