Experimental signatures of a three-dimensional quantum spin liquid in effective spin-1/2 Ce2Zr2O7 pyrochlore
Experimental signatures of a three-dimensional quantum spin liquid in effective spin-1/2 Ce2Zr2O7 pyrochlore
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DOI：
10.1038/s41567-019-0577-6
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发表时间：
2019-10-01
期刊：
影响因子：
19.6
通讯作者：
Dai, Pengcheng
中科院分区：
文献类型：
--
作者：
Gao, Bin;Chen, Tong;Dai, Pengcheng
量子自旋液体是一种物质状态，其中未成对电子的自旋虽然纠缠，但即使在零温度下也不显示磁序。实现量子自旋液体是凝聚态物理学长期追求的目标。虽然在二维自旋1/2 kagome晶格ZnCu 3（OD）（6）Cl-2和三角晶格YbMgGaO 4上的中子散射实验已经发现了在非常低的温度下量子自旋液体的标志（连续的磁激发）的证据，但磁性和非磁性位点化学无序的存在使数据的解释复杂化。最近，三维Ce 3+烧绿石晶格Ce 2Sn 2 O 7已被建议作为一个干净的，有效的自旋1/2量子自旋液体候选人，但自旋激发连续的证据仍然缺失。在这里，我们使用热力学，μ子自旋弛豫和中子散射实验单晶Ce 2 Zr 2 O 7，一种化合物同构Ce 2Sn 2 O 7，以证明没有磁有序和存在的自旋激发连续在35 mK。由于中子衍射和漫散射测量没有发现氧缺乏和磁性/非磁性离子无序的证据，Ce 2 Zr 2 O 7可能是具有最小磁性和非磁性化学无序的三维烧绿石晶格量子自旋液体材料。
A quantum spin liquid is a state of matter where unpaired electrons' spins, although entangled, do not show magnetic order even at the zero temperature. The realization of a quantum spin liquid is a long-sought goal in condensed-matter physics. Although neutron scattering experiments on the two-dimensional spin-1/2 kagome lattice ZnCu3(OD)(6)Cl-2 and triangular lattice YbMgGaO4 have found evidence for the hallmark of a quantum spin liquid at very low temperature (a continuum of magnetic excitations), the presence of magnetic and non-magnetic site chemical disorder complicates the interpretation of the data. Recently, the three-dimensional Ce3+ pyrochlore lattice Ce2Sn2O7 has been suggested as a clean, effective spin-1/2 quantum spin liquid candidate, but evidence of a spin excitation continuum is still missing. Here, we use thermodynamic, muon spin relaxation and neutron scattering experiments on single crystals of Ce2Zr2O7, a compound isostructural to Ce2Sn2O7, to demonstrate the absence of magnetic ordering and the presence of a spin excitation continuum at 35 mK. With no evidence of oxygen deficiency and magnetic/non-magnetic ion disorder seen by neutron diffraction and diffuse scattering measurements, Ce2Zr2O7 may be a three-dimensional pyrochlore lattice quantum spin liquid material with minimum magnetic and non-magnetic chemical disorder.