Spinon, soliton and breather in the spin-1/2 antiferromagnetic chain KCuGaF6
Spinon, soliton and breather in the spin-1/2 antiferromagnetic chain KCuGaF6
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自旋1/2反铁磁链KCuGaF6中的自旋子、孤子和呼吸器
DOI：
10.1103/physrevb.92.174412
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发表时间：
2015
影响因子：
3.7
通讯作者：
K. Kakurai
中科院分区：
文献类型：
--
作者：
I. Umegaki;H. Tanaka;N. Kurita;T. Ono;M. Laver;C. Niedermayer;C. Rüegg;S. Ohira-Kawamura;K. Nakajima;K. Kakurai
用非弹性中子散射和比热测量研究了一维反铁磁体在垂直于平面的零磁场和有限磁场中的元激发，尽管交换作用K很大，但在50 mK以下没有长程磁有序。在零磁场下，观察到了定义明确的自旋激发。自旋子激发的des Cloizeaux和Pearson [J. des Cloizeaux和J. J. Pearson，Phys.Rev.128，2131（1962）PHRVAO 0031 -899X10.1103/PhysRev.128.2131]模式的能量比用上述交换常数计算的能量稍大。这种差异主要归因于大的Dzyaloshinsky-Moriya [T. Moriya，Phys. Rev. 120，91（1960）PHRVAO 0031 -899X10.1103/PhysRev.120.91]与交变磁场的相互作用由量子sine-Gordon模型表示，对于该模型，低能元激发由孤子和反孤子以及它们的被称为呼吸子的束缚态组成。vector.in与理论预测不同的是，发现孤子的能量小于第一个呼吸子的能量，尽管第一个呼吸子的能量与以前的电子自旋共振测量中观察到的能量一致。
Elementary excitations of theone-dimensional antiferromagnetwere investigated by inelastic neutron scattering in zero and finite magnetic fields perpendicular to theplane combined with specific heat measurements.exhibits no long-range magnetic ordering down to 50 mK despite the large exchange interactionK. At zero magnetic field, well-defined spinon excitations were observed. The energy of the des Cloizeaux and Pearson [J. des Cloizeaux and J. J. Pearson, Phys. Rev. 128, 2131 (1962)PHRVAO0031-899X10.1103/PhysRev.128.2131] mode of the spinon excitations is somewhat larger than that calculated with the above exchange constant. This discrepancy is mostly ascribed to the effectiveanisotropy arising from the large Dzyaloshinsky-Moriya [T. Moriya, Phys. Rev. 120, 91 (1960)PHRVAO0031-899X10.1103/PhysRev.120.91] interaction with an alternating D vector.in a magnetic field is represented by the quantum sine-Gordon model, for which low-energy elementary excitations are composed of solitons and antisolitons and their bound states called breathers. Unlike the theoretical prediction, it was found that the energy of a soliton is smaller than that of the first breather, although the energy of the first breather coincides with that observed in a previous electron spin resonance measurement.