Fluence-dependent femtosecond quasiparticle and Eu2+ spin relaxation dynamics in EuFe2(As,P)2

A. Pogrebna, T. Mertelj, G. Cao, Z. A. Xu, D. Mihailovic
2016 Physical review B  
We investigated temperature and fluence dependent dynamics of the time resolved optical reflectivity in undoped spin-density-wave (SDW) and doped superconducting (SC) EuFe_2(As,P)_2 with emphasis on the ordered Eu^2+-spin temperature region. The data indicate that the SDW order coexists at low temperature with the SC and Eu^2+-ferromagnetic order. Increasing the excitation fluence leads to a thermal suppression of the Eu^2+-spin order due to the crystal-lattice heating while the SDW order is suppressed nonthermally at a higher fluence.
doi:10.1103/physrevb.94.144519 fatcat:wuwgynpqxzhnvn2bxnoa3ka5ca