Ultrafast pump-probe spectroscopy of multiferroic TbMnO$_{3}$

TbMnO$_{3}$, exhibiting simultaneously both magnetic and ferroelectric phases, is an excellent multiferroic candidate for demonstrating the strong coupling between different degrees of freedom, i.e. spin, orbital and charge order. Previously, ultrafast optical pump-probe spectroscopy has proven to be an ideal technique for unraveling the interplay between different orders in the time domain. In this work, we used this technique to study ultrafast dynamics in multiferroic TbMnO$_{3}$. At low temperatures, we initially observed an extraordinarily slow rising process, with a timescale of tens of picoseconds, followed by another decay process with a relaxation time of hundreds of picoseconds. An analysis of these two processes as a function of temperature reveals the influence of the magnetic and ferroelectric phase transitions on carrier dynamics in TbMnO$_{3}$, which agrees well with other experimental results.