Fig. 5: Computed photoinduced changes in charge and spin density in FeRh.
From: Subpicosecond metamagnetic phase transition in FeRh driven by non-equilibrium electron dynamics
a, b Changes in the charge density n(r, tf) − neq(r) and (c) spin density \({S}_{z}({{{{{{{\bf{r}}}}}}}},{t}_{f})-{S}_{z}^{eq}({{{{{{{\bf{r}}}}}}}})\) at the end of the laser pulse (t = tf) with respect to the equilibrium configuration. Densities are in atomic units ([\(e/{a}_{0}^{3}\)] and [\({\mu }_{{{\mbox{B}}}}/{a}_{0}^{3}\)], where a0 = 5.29 × 10−11 m is the Bohr radius. 0.25 electron per unit cell corresponds to a density of \(7\times 1{0}^{-4}\ e/{a}_{0}^{3}\).) on two different FeRh{111}-planes: the plane just below the Fe(↑) atoms (a) and the plane containing the Rh atoms (b, c). Fe and Rh atom positions are indicated by red and gray segments of the lattice, respectively. Charge is transferred from the occupied (bonding) orbitals of Rh atoms (panel b), to the unoccupied (anti-bonding) orbitals of Rh and Fe (a). Since the Fe anti-bonding levels are filled in this process, the local Fe spin density is reduced. As a result, there is a redistribution of spin density around the Rh atoms and a reduction of the local spin moment at the Fe atoms (c). The movies in the Supplementary Information show the simulated time evolution of the charge density variations at the Fe and Rh sites as represented in (a) and (b) at the beginning and the end of the laser pulse.
