Localized spin‐flip excitations in hexagonal HoMnO3

Growing demands for ultra‐fast switching of spins have turned attention to optically controlled spintronics, which indeed has recently been demonstrated promising. Here we report localized spin‐flip excitations revealed by resonance inelastic light scattering on hexagonal holmium manganite thin films with the magnetic manganese ions substituted by the nonmagnetic gallium ions (HoMn1 − xGaxO3). Our analyses on a broad Raman peak support that the corresponding spin excitation is associated with flipping of all three Mn3+ spins in the elementary trimer of manganese ions and hence maintains the same excitation energy determined by the intrinsic spin–spin interaction between Mn3+ ions. The nonmagnetic gallium ions only reduce the population of the spin excitations by breaking the spin‐frustrated triangular network. Such localized spin‐flip excitations show another promise towards optically controlled spin devices. The origin of the spin excitations in the hexagonal HoMnO3 below the Néel ordering temperature is investigated by resonance inelastic light scattering. Our analyses on experimental data along with theoretical modeling on the spin‐excitation peak support that the corresponding spin excitations are associated with flipping of all three Mn3+ spins in the elementary trimer of manganese ions. The spin‐flip excitations are limited in the Mn triangular network. Such localized spin‐flip excitations show another promise towards optically controlled spin devices.