Ni₁₋ₓVₓ铁磁相内的量子格里菲斯相

Quantum Griffiths Phase Inside the Ferromagnetic Phase of Ni_{1-x}V_{x}.

作者信息

Wang Ruizhe, Gebretsadik Adane, Ubaid-Kassis Sara, Schroeder Almut, Vojta Thomas, Baker Peter J, Pratt Francis L, Blundell Stephen J, Lancaster Tom, Franke Isabel, Möller Johannes S, Page Katharine

机构信息

Physics Department, Kent State University, Kent, Ohio 44242, USA.

Department of Physics, Missouri University of Science and Technology, Rolla, Missouri 65409, USA.

出版信息

Phys Rev Lett. 2017 Jun 30;118(26):267202. doi: 10.1103/PhysRevLett.118.267202. Epub 2017 Jun 28.

DOI:10.1103/PhysRevLett.118.267202

PMID:28707923

Abstract

We study by means of bulk and local probes the d-metal alloy Ni_{1-x}V_{x} close to the quantum critical concentration, x_{c}≈11.6%, where the ferromagnetic transition temperature vanishes. The magnetization-field curve in the ferromagnetic phase takes an anomalous power-law form with a nonuniversal exponent that is strongly x dependent and mirrors the behavior in the paramagnetic phase. Muon spin rotation experiments demonstrate inhomogeneous magnetic order and indicate the presence of dynamic fluctuating magnetic clusters. These results provide strong evidence for a quantum Griffiths phase on the ferromagnetic side of the quantum phase transition.

摘要

我们通过体探针和局域探针研究了接近量子临界浓度(x_{c}≈11.6%)的d金属合金(Ni_{1-x}V_{x})，在该浓度下铁磁转变温度消失。铁磁相中的磁化场曲线呈现出异常的幂律形式，其非普适指数强烈依赖于(x)，并反映了顺磁相中的行为。μ子自旋旋转实验证明了磁序的不均匀性，并表明存在动态波动的磁团簇。这些结果为量子相变铁磁侧的量子格里菲斯相提供了有力证据。