Magnetization dynamics and the Mn3+ d-d excitation of hexagonal HoMnO3 single crystals using wavelength-tunable time-resolved femtosecond spectroscopy

Abstract

We analyze the photo-induced carrier and magnetization dynamics in antiferromagnetic (AFM) HoMnO3 single crystals, delineated by wavelength-dependent femtosecond spectroscopy. The emergence of long-range and short-range magnetic order are unambiguously revealed in association with an abnormal blueshift of Mn3+ 3d level around the Neacuteel temperature and the slope variation in the temperature-dependent transient reflectivity change (Delta R/R) near the Neacuteel transition, respectively. Furthermore, the disturbance (in ps time scale) of the AFM ordering and its reordering time (in a few 100 ps time scale) are clearly identified in the negative Delta R/R.</p>.