论文标题
具有强型单离子各向异性的自旋隙磁铁中的抗磁共振共振
Antiferromagnetic resonance in a spin-gap magnet with strong single-ion anisotropy
论文作者
论文摘要
Quasi-One维磁铁NICL $ _2 \ CD $ 4SC（NH $ _2 $）$ _ 2 $通常作为DTN订购，在零字段中不会订购$ t = 0 $：由于强大的单离子离子偏置的强大的单离子各向异性，这是$ s = 1 $ ni $ ni $ ni $ ni $ ni $ ni $ ni $ ni $ ni $ ni $ ni;从$ s_z = \ pm 1 $通过能量差距进行激发。一旦沿主要各向异性轴施加磁场，缝隙就会以$ b_ {c1} = 2.18 $ t的限制，并出现了场诱导的抗fiferromagnetic Order。该场引起的有序状态的低能激发光谱包括两个激励分支，其中一个必须是无间隙的金石模式。在野外诱导的DTN有序状态中对激发光谱的最新研究（T.Soldatov等，Phys.Rev.B 101，104410（2020））表明，随着磁场偏离主对称轴的偏差，Goldstone Mode被覆盖。本文提出了简单描述准磁共振的准量子量子$ s = 1 $磁铁，具有强烈的单离子各向异性。所使用的方法是基于针对各向异性自旋链的强耦合模型与抗势磁共振的常规平均场模型的组合。所得模型符合已知的实验结果，而无需其他调整参数。
Quasi-one-dimensional magnet NiCl$_2\cdot$4SC(NH$_2$)$_2$, usually abbreviated as DTN, does not order at zero field down to $T=0$: due to the strong single-ion anisotropy of the "easy plane" type acting on $S=1$ Ni$^{2+}$ ions, the $S_z=0$ ground state is separated from $S_z=\pm 1$ excitations by an energy gap. Once the magnetic field is applied along the main anisotropy axis, the gap closes at $B_{c1}=2.18$ T and the field-induced antiferromagnetic order arises. The low-energy excitations spectrum of this field-induced ordered state includes two branches of excitations, one of them have to be a gapless Goldstone mode. Recent studies of excitations spectrum in a field-induced ordered state of DTN (T.Soldatov et.al, Phys.Rev.B 101, 104410 (2020)) have revealed that Goldstone mode became gapped as magnetic field deviates from the main symmetry axis. This paper proposes simple description of antiferromagnetic resonance modes of quasi-one-dimensional quantum $S=1$ magnet with strong single-ion anisotropy. The approach used is based on a combination of the strong coupling model for the anisotropic spin chain with the conventional mean-field model of antiferromagnetic resonance. The resulting model fits to the known experimental results without additional tuning parameters.
