Magnetic Bloch Oscillations and domain wall dynamics in a near-Ising ferromagnetic chain
Ursula B. Hansen, Olav F. Syljuåsen, Jens Jensen, Turi K. Schäffer, Christopher R. Andersen, Jose A. Rodriguez-Rivera, Niels B. Christensen, Kim Lefmann
When charged particles in periodic lattices are subjected to a constant electric field, they respond by oscillating. Here we demonstrate that the magnetic analogue of these Bloch oscillations are realised in a one-dimensional ferromagnetic easy axis chain. In this case, the "particle" undergoing oscillatory motion in the presence of a magnetic field is a domain wall. Inelastic neutron scattering reveals three distinct components of the low energy spin-dynamics including a signature Bloch oscillation mode. Using parameter-free theoretical calculations, we are able to account for all features in the excitation spectrum, thus providing detailed insights into the complex dynamics in spin-anisotropic chains.
A hierarchy of bound states in the 1D ferromagnetic Ising chain CoNb$_2$O$_6$ investigated by high resolution time-domain terahertz spectroscopy
在零外加磁场下，利用高分辨时域太赫兹光谱研究了一维铁磁伊辛链化合物CoNb $_2$ O $_6$中的扭结束缚态.当磁序在低温下发展时，九个束缚态的扭结变得可见。它们的能量可以非常好地用一维线性势薛定谔方程的Airy函数解来模拟。这一系列的束缚态在接近最低束缚态能量的两倍的阈值能量处终止。在这个能量标度以上，我们观察到一个广泛的功能与两个粒子连续的发病相一致。在能量低于这个阈值，我们观察到一个突出的激发，我们解释为一个新的束缚态的束缚态-两对扭结相邻的链。
Thickness dependent Curie temperature and power-law behavior of layering transitions in ferromagnetic classical and quantum thin films described by Ising, XY and Heisenberg models
Pressure-induced ferromagnetism with strong Ising-type anisotropy in YbCu$_2$Si$_2$
我们报告直流磁性测量YbCu $_2$ Si $_2$在10 GPa以上的压力使用微型陶瓷砧室。YbCu $_2$ Si $_2$在8 GPa压力下发生了从非磁性相到磁性相的压力诱导相变。我们发现一个自发的直流磁化在压力诱导阶段高于9.4 GPa。测定了2.0K时铁磁转变温度Tc和自发磁矩m_0的压力依赖关系。宏观测量的m_0值不到穆斯堡尔实验的一半。这种差异可以归因于铁磁相和顺磁相之间的空间相分离。这种分离表明，压力引起的相边界之间的顺磁和铁磁状态是一阶的。此外，我们还研究了压致铁磁态的磁各向异性。压力对磁化强度的影响沿磁易$c$ -轴的磁场比沿硬$a$ -轴的磁场大得多。压力诱导相具有很强的Ising型单轴各向异性，与针对YbCu $_2$ Si $_2$提出的两种晶体电场（CEF）模型一致。
