论文标题
S = 3/2磁铁$β$ -CACR $ _2 $ o $ $ _4 $从一开始到两毫克激发
From one- to two-magnon excitations in the S=3/2 magnet $β$-CaCr$_2$O$_4$
论文作者
论文摘要
我们采用中子光谱法来测量s = 3/2磁铁$β$ -CACR $ -CACR $ _2 $ o $ $ _4 $（t $ _n $ = 21 K）中的磁化动力学。在有序状态下的低能波动类似于来自不相称的基态的大S线性自旋波。但是，在较高的能量转移下，这些半古典和谐波动力学被能量和动量扩大的激发连续体取代。采用能量和动量保护所需的运动学约束，中子散射的总和规则以及与精确的对角度计算的比较，我们表明，高能传输处的动力学类似于低S的一维量子波动。 $β$ -CACR $ _2 $ o $ _4 $代表了古典néel和量子阶段边界的磁铁的一个示例，显示了双重特征。
We apply neutron spectroscopy to measure the magnetic dynamics in the S=3/2 magnet $β$-CaCr$_2$O$_4$ (T$_N$=21 K). The low-energy fluctuations, in the ordered state, resemble large-S linear spin-waves from the incommensurate ground state. However, at higher energy transfers, these semi-classical and harmonic dynamics are replaced by an energy and momentum broadened continuum of excitations. Applying kinematic constraints required for energy and momentum conservation, sum rules of neutron scattering, and comparison against exact diagonalization calculations, we show that the dynamics at high-energy transfers resemble low-S one-dimensional quantum fluctuations. $β$-CaCr$_2$O$_4$ represents an example of a magnet at the border between classical Néel and quantum phases, displaying dual characteristics.
