论文标题
疾病引起的旋转波在三角晶格量子旋转候选Ybzngao $ _4 $中的宽阔拓宽
Disorder-induced broadening of the spin waves in a triangular-lattice quantum-spin-liquid candidate YbZnGaO$_4$
论文作者
论文摘要
疾病在量子自旋液体的研究中很重要，但其在自旋动力学上的作用仍然难以捉摸。在这里，我们通过研究三角形降低的磁铁沮丧的磁铁ybzngao $ _4 $的磁场依赖性，探索了障碍效应。沿着$ C $轴施加2.5 t的中间场，零场的宽连续体在能量和动量上都变得更加涂抹。在最多10吨的场上，它完全偏振了磁矩，我们观察到$ \ sim $ \ sim $ 1.4 meV的透明自旋波激发与带宽相当。但是，光谱大大扩展。可以通过执行经典的蒙特卡洛模拟来重现零场和高场的激发光谱，这些模拟考虑了非磁性Zn $^{2+} $和ga $^{3+} $ ions的随机位点混合而产生的疾病效应。这些结果阐明了疾病在拓宽磁激励光谱中的关键作用，并模仿沮丧的量子磁铁中的自旋液体特征。
Disorder is important in the study of quantum spin liquids, but its role on the spin dynamics remains elusive. Here, we explore the disorder effect by investigating the magnetic-field dependence of the low-energy magnetic excitations in a triangular-lattice frustrated magnet YbZnGaO$_4$ with inelastic neutron scattering. With an intermediate field of 2.5 T applied along the $c$-axis, the broad continuum at zero field becomes more smeared both in energy and momentum. With a field up to 10 T, which fully polarizes the magnetic moments, we observe clear spin-wave excitations with a gap of $\sim$1.4 meV comparable to the bandwidth. However, the spectra are significantly broadened. The excitation spectra both at zero and high fields can be reproduced by performing classical Monte Carlo simulations which take into account the disorder effect arising from the random site mixing of nonmagnetic Zn$^{2+}$ and Ga$^{3+}$ ions. These results elucidate the critical role of disorder in broadening the magnetic excitation spectra and mimicking the spin-liquid features in frustrated quantum magnets.
