Unraveling the interplay

Unraveling the interplay
Unraveling the interplay of electron-phonon coupling, pseudogap, and superconductivity in CsCa$_2$Fe$_4$As$_4$F$_2$

The quasiparticle relaxation dynamics of the iron-based superconductor CsCa$_2$Fe$_4$As$_4$F$_2$ ($T_c$ $sim$ 29 K) were investigated using ultrafast optical spectroscopy. A pseudogap ($Δ_{PG}$ $approx$ 3.3 meV) was observed to open below $T^{ast}$ $approx$ 60 K, prior to the emergence of a supercon…