2010/02/25 by Johan Bielecki, J. Bielecki, R. Rauer +5
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Atomic physics #Condensed matter physics #Electronic and Structural Properties of Oxides #Excited state #Magnetic and transport properties of perovskites and related materials #Materials science #Photoexcitation #Physics #Picosecond #Quantum mechanics #Thermodynamics #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.81.064434
published as Physical Review B 81, 064434 (2010) · 6 pages, 5 figures http://link.aps.org/doi/10.1103/PhysRevB.81.064434 v2: Abstract corrected
openalex publication_date 2010/02/25 · arxiv created 2010/02/26 · arxiv updated 2010/02/26 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We investigate the low-temperature electron, lattice, and spin dynamics of LaMnO3 (LMO) and La0.7Ca0.3MnO3 (LCMO) by resonant pump-probe reflectance spectroscopy. Probing the high-spin d\text\ensuremath-d transition as a function of time delay and probe energy, we compare the responses of the Mott insulator and the double-exchange metal to the photoexcitation. Attempts have previously been made to describe the subpicosecond dynamics of colossal magnetoresistance manganites in terms of a phenomenological three-temperature model describing the energy transfer between the electron, lattice, and spin subsystems followed by a comparatively slow exponential decay back to the ground state. However, conflicting results have been reported. Here we first show clear evidence of an additional component in the long-term relaxation due to film-to-substrate heat diffusion and then develop a modified three-temperature model that gives a consistent account for this feature. We confirm our interpretation by using it to deduce the band gap in LMO. In addition, we also model the nonthermal subpicosecond dynamics, giving a full account of all observed transient features both in the insulating LMO and the metallic LCMO.