Gapless quantum spin liquid ground state in the two-dimensional spin-1/2 triangular antiferromagnet YbMgGaO4.
Gapless quantum spin liquid ground state in the two-dimensional spin-1/2 triangular antiferromagnet YbMgGaO4.
复制标题
在二维自旋1/2三角抗fiferromagnet ybmggao4中无间隙量子自旋液态基态。
DOI：
10.1038/srep16419
复制
发表时间：
2015-11-10
影响因子：
4.6
通讯作者：
Zhang Q
中科院分区：
文献类型：
--
作者：
Li Y;Liao H;Zhang Z;Li S;Jin F;Ling L;Zhang L;Zou Y;Pi L;Yang Z;Wang J;Wu Z;Zhang Q
量子自旋液体（QSL）是一种即使在0 K下也无法冻结自旋的新型物质状态。在凝聚态物理学中，通过实验寻找结构完美的候选者是一个巨大的挑战。本文报道了一种新的自旋为1/2的对称三角形反铁磁体YbMgGaO 4的成功合成。该化合物具有理想的二维空间各向同性磁性三角晶格，不存在位置混合磁缺陷和反对称Dzyaloshinsky-Moriya（DM）相互作用。没有自旋冻结下降到60 mK（尽管θw ~ −4 K），幂律温度依赖的热容和非零磁化率在低温下表明，YbMgGaO 4是一个有前途的无带隙（≤| θw|/100）QSL候选人。用非磁性参考LuMgGaO 4精确确定的剩余自旋熵接近于零（<0.6%）。这表明在最低的测量温度下，实验上已经实现了受抑自旋系统的可能的QSL基态。
Quantum spin liquid (QSL) is a novel state of matter which refuses the conventional spin freezing even at 0 K. Experimentally searching for the structurally perfect candidates is a big challenge in condensed matter physics. Here we report the successful synthesis of a new spin-1/2 triangular antiferromagnet YbMgGaO4 with symmetry. The compound with an ideal two-dimensional and spatial isotropic magnetic triangular-lattice has no site-mixing magnetic defects and no antisymmetric Dzyaloshinsky-Moriya (DM) interactions. No spin freezing down to 60 mK (despite θw ~ −4 K), the power-law temperature dependence of heat capacity and nonzero susceptibility at low temperatures suggest that YbMgGaO4 is a promising gapless (≤|θw|/100) QSL candidate. The residual spin entropy, which is accurately determined with a non-magnetic reference LuMgGaO4, approaches zero (<0.6%). This indicates that the possible QSL ground state (GS) of the frustrated spin system has been experimentally achieved at the lowest measurement temperatures.