Title: Exchange enhanced switching by alternating fields in quantum antiferromagnets Show Chinese title

Title: 量子反铁磁体中通过交变场增强的开关转换

Abstract: Information can be stored magnetically in antiferromagnets ultrafast since their characteristic times are on the picosecond scale. Various spin torques have proven to be important for efficient and high-speed magnetic memories. So far, this has been understood on the classical level by solving the equations of motion for macrospins describing the collective motion of the sublattice magnetizations. Since spins and hence magnetizations are deeply rooted in quantum mechanics, we show that the exchange enhanced manipulation of sublattice magnetizations extends to quantum antiferromagnets as well. To this end, we solve the time-dependent mean-field equations for Schwinger boson theory under external alternating magnetic fields. Exchange enhancement persists on the quantum level which includes dephasing effects. Significantly lower fields are sufficient to control the sublattice magnetization than for uniform fields which holds great promises for the realization of ultrafast magnetic storage devices. Show Chinese abstract

Abstract: 信息可以以超快的方式存储在反铁磁材料中，因为它们的特征时间处于皮秒量级。 各种自旋力矩已被证明对于高效且高速的磁性存储至关重要。 到目前为止，这已经在经典层面上通过求解描述亚点阵磁化集体运动的宏观自旋运动方程来理解。 由于自旋和磁化从根本上与量子力学相关，我们展示了交换增强的亚点阵磁化操控同样适用于量子反铁磁体。 为此，我们在外加交变磁场下求解了施温格玻色子理论的时间相关平均场方程。 交换增强效应在量子层面依然存在，其中包括退相位效应。 与均匀磁场相比，显著更低的磁场就足以控制亚点阵磁化，这为实现超快速磁存储设备带来了巨大希望。