M. Porer, L. Rettig, E. M. Bothschafter, V. Esposito, R. B. Versteeg, P. H. M. van Loosdrecht, M. Savoini, J. Rittmann, M. Kubli, G. Lantz, O. J. Schumann, A. A. Nugroho, M. Braden, G. Ingold, S. L. Johnson, P. Beaud, and U. Staub:
Phys. Rev. B 101 (7), 075119 (2020), pp. 9;
Time-resolved x-ray diffraction experiments on the half-doped single-layered manganite Pr0.5Ca1.5MnO4 are used to monitor the ultrafast photoinduced dynamics of the structural distortion associated with the charge and orbital ordering (CO/OO). As in the nonlayered three-dimensional counterpart, the ordered phase melts in less than 100 fs after 800-nm photoexcitation and subsequently partially recovers due to thermal equilibration of electronic and vibrational systems. Photoexciting Pr0.5Ca1.5MnO4 below the transition temperature of a second structural phase transition that occurs around 146 K (deep inside the CO/OO phase) releases this structural transition, but progresses on a much slower timescale. This additional reduction of crystal symmetry, which we ascribe to a further tilt of the oxygen octahedra, can thus be considered to be only weakly coupled to CO/OO. Furthermore, static hard-x-ray and resonant soft-x-ray diffraction at the MnL2,3 edges experiments identify correlations between structural distortions and electronic order in thermal equilibrium.
The original publication is available by link DOI: 10.1103/PhysRevB.101.075119