Field-Driven Quantum Criticality in the Spinel Magnet ZnCr2Se4
Field-Driven Quantum Criticality in the Spinel Magnet ZnCr2Se4
复制标题
尖晶石磁铁 ZnCr2Se4 中的场驱动量子临界
DOI：
10.1103/physrevlett.120.147204
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发表时间：
2018
影响因子：
8.6
通讯作者：
Sun X. F.
中科院分区：
文献类型：
--
作者：
Gu C. C.;Zhao Z. Y.;Chen X. L.;Lee M.;Choi E. S.;Han Y. Y.;Ling L. S.;Pi L.;Zhang Y. H.;Chen G.;Yang Z. R.;Zhou H. D.;Sun X. F.
我们报告详细的直流和交流磁化率，比热，和热导率测量的挫折磁铁。在低温下，随着磁场的增加，这种尖晶石材料经历了一系列从螺旋自旋状态到螺旋自旋状态，然后到完全极化状态的自旋状态转变。我们的结果表明，从螺旋自旋态到全极化态的直接量子相变。当系统接近量子临界时，我们发现自旋的强烈量子涨落具有非常规依赖的比热和与温度无关的热输运平均自由程等行为。我们完成了外部磁场下的完整相图，并提出了受抑量子临界的可能性与扩展密度的临界模式来解释不寻常的低能量激发附近的临界。我们的研究结果表明，这是一个罕见的例子，三维磁铁表现出非常规性质的场驱动量子临界。
We report detailed dc and ac magnetic susceptibilities, specific heat, and thermal conductivity measurements on the frustrated magnet. At low temperatures, with an increasing magnetic field, this spinel material goes through a series of spin state transitions from the helix spin state to the spiral spin state and then to the fully polarized state. Our results indicate a direct quantum phase transition from the spiral spin state to the fully polarized state. As the system approaches the quantum criticality, we find strong quantum fluctuations of the spins with behaviors such as an unconventional-dependent specific heat and temperature-independent mean free path for the thermal transport. We complete the full phase diagram ofunder the external magnetic field and propose the possibility of frustrated quantum criticality with extended densities of critical modes to account for the unusual low-energy excitations in the vicinity of the criticality. Our results reveal thatis a rare example of a 3D magnet exhibiting a field-driven quantum criticality with unconventional properties.