论文标题
磁化的超快音调切换
Ultrafast phononic switching of magnetization
论文作者
论文摘要
通过耦合高频模式的微妙激发来确定更改顺序参数的有效途径是超快相变领域的最终目标。这是磁性方向特别有趣的研究方向，其中磁化逆转需要自旋和晶格激发之间的耦合。尽管有几次尝试，但尚未证明通过声音模式的谐振泵进行磁状态之间的切换。在这里，我们展示了磁石榴膜中纵向光学声子模式的超快共振激发如何将磁化磁化切换为特殊的四极磁磁体模式，从而明确揭示了开关的磁弹性机制。相反，强烈吸收的横向声子模式的激发仅导致热消电效应。
Identifying an efficient pathway to change the order parameter via a subtle excitation of the coupled high-frequency mode is the ultimate goal of the field of ultrafast phase transitions. This is an especially interesting research direction in magnetism, where the coupling between spin and lattice excitations is required for magnetization reversal. Despite several attempts however, the switching between magnetic states via resonant pumping of phonon modes has not yet been demonstrated. Here we show how an ultrafast resonant excitation of the longitudinal optical phonon modes in magnetic garnet films switches magnetization into a peculiar quadrupolar magnetic domain pattern, unambiguously revealing the magneto-elastic mechanism of the switching. In contrast, the excitation of strongly absorbing transverse phonon modes results in thermal demagnetization effect only.
