Max-Planck-Institut for the Physics of Complex Systems, Dresden, Germany.
Phys Rev Lett. 2012 Sep 21;109(12):127601. doi: 10.1103/PhysRevLett.109.127601. Epub 2012 Sep 19.
We interpret recent measurements of the zero field muon relaxation rate in the magnetic pyrochlore Dy(2)Ti(2)O(7) as resulting from the quantum diffusion of muons in the material. In this scenario, the plateau observed at low temperature (< 7 K) in the relaxation rate is due to coherent tunneling of muons through a spatially disordered spin state and not to any magnetic fluctuations persisting at low temperature. Two further regimes either side of a maximum relaxation rate at T* = 50 K correspond to a crossover between tunneling and incoherent activated hopping motion of the muon. Our fit of the experimental data is compared with the case of muonium diffusion in KCl.
我们将最近在 Dy(2)Ti(2)O(7) 磁反铁榴石中测量的零场 μ 子弛豫率解释为 μ 子在材料中的量子扩散所致。在这种情况下，在低温（<7 K）下观察到的弛豫率的平台是由于 μ 子通过空间无序的自旋态的相干隧穿，而不是由于任何低温下持续存在的磁涨落。在 T*=50 K 时最大弛豫率的两侧的另外两个区域对应于隧穿和 μ 子的非相干激活跳跃运动之间的交叉。我们对实验数据的拟合与 KCl 中 μ 子扩散的情况进行了比较。
