Photoinduced magnetization dynamics is investigated in chemically ordered $(\mathrm{LaMnO}_3)_{2n}/(\mathrm{SrMnO}_3)_n$ superlattices using the time-resolved magneto-optic Kerr effect. A monotonic frequency-field dependence is observed for the $n=1$ superlattice, indicating a single spin population consistent with a homogeneous hole distribution. In contrast, for $n\geq2$ superlattices, a large precession frequency is observed at low fields indicating the presence of an exchange torque in the dynamic regime. We propose a model that ascribes the emergence of exchange torque to the coupling between two spin populations -- viscous and fast spins.
Exchange interactions and finite-temperature magnetism in (111)-oriented (LaMnO$_3$)$_{2n}$|(SrMnO$_3$)$_n$ superlattices
Institute of Physics, Nicolaus Copernicus University（尼古拉·哥白尼大学物理研究所）；School of Physics, Engineering and Technology, University of York（约克大学物理、工程与技术学院）；Department of Physics and Institute of Quantum Convergence and Technology, Kangwon National University（江原国立大学物理系及量子融合技术研究所）；Department of Energy Technology, Korea Institute of Energy Technology (KENTECH)（韩国能源技术研究院能源技术部）；Department of Physics and Astronomy, Uppsala University（乌普萨拉大学物理与天文系）
Strain-induced structural transitions in (111)-oriented (LaMnO$_3$)$_{2n}|$(SrMnO$_3$)$_n$ superlattices
Institute of Physics, Nicolaus Copernicus University（尼古拉·哥白尼大学物理研究所）；School of Physics, Engineering and Technology, University of York（约克大学物理、工程与技术学院）；Department of Physics, School of Natural and Computing Sciences, University of Aberdeen（阿伯丁大学自然与计算科学学院物理系）；Department of Physics and Institute of Quantum Convergence and Technology, Kangwon National University（江原国立大学物理系及量子融合技术研究所）；Department of Physics and Astronomy, Uppsala University（乌普萨拉大学物理与天文学系）
