Higgs transition from a magnetic Coulomb liquid to a ferromagnet in Yb₂Ti₂O₇.
Higgs transition from a magnetic Coulomb liquid to a ferromagnet in Yb₂Ti₂O₇.
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DOI：
10.1038/ncomms1989
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发表时间：
2012
影响因子：
16.6
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中科院分区：
文献类型：
--
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在一类被称为自旋冰的受抑磁体中，磁单极子作为经典缺陷出现，并通过磁库仑定律相互作用。在量子力学相互作用下，这些磁荷由分形玻色子准粒子（自旋子）携带，自旋子可以通过希格斯机制通过一级跃迁进行玻色-爱因斯坦凝聚。在这里，我们报告的证据希格斯过渡从磁性库仑液体铁磁体在单晶Yb 2 Ti 2 O 7。极化中子散射实验表明，在TC~0.21 K温度下，冷却过程中产生的[111]-棒扩散散射和夹点特征突然被抑制，在此温度下观察到磁布拉格峰和中子自旋的完全去极化，并伴有热滞，表明发生了一级铁磁相变。我们的结果解释的基础上的量子自旋冰模型，其高温相有效地描述为磁性库仑液体，而基态显示出近共线的铁磁性与带隙自旋激发。量子自旋冰是物质的一种磁性状态，它可以充当电磁激发的宿主。利用极化中子散射，Chang等人证明了量子自旋冰材料钛酸镱经历了从库仑液体到铁磁相的出现磁单极子的希格斯跃迁。
In a class of frustrated magnets known as spin ice, magnetic monopoles emerge as classical defects and interact via the magnetic Coulomb law. With quantum-mechanical interactions, these magnetic charges are carried by fractionalized bosonic quasi-particles, spinons, which can undergo Bose–Einstein condensation through a first-order transition via the Higgs mechanism. Here, we report evidence of a Higgs transition from a magnetic Coulomb liquid to a ferromagnet in single-crystal Yb2Ti2O7. Polarized neutron scattering experiments show that the diffuse [111]-rod scattering and pinch-point features, which develop on cooling are suddenly suppressed below TC~0.21 K, where magnetic Bragg peaks and a full depolarization of the neutron spins are observed with thermal hysteresis, indicating a first-order ferromagnetic transition. Our results are explained on the basis of a quantum spin-ice model, whose high-temperature phase is effectively described as a magnetic Coulomb liquid, whereas the ground state shows a nearly collinear ferromagnetism with gapped spin excitations. Quantum spin ice is a magnetic state of matter which can play host to monopole excitations. Using polarized neutron scattering, Chang et al. show that the quantum spin ice material ytterbium titanate undergoes a Higgs transition of emergent magnetic monopoles from a Coulomb liquid to a ferromagnetic phase.
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影响因子：
19.6
作者：
Giblin, S. R.;Bramwell, S. T.;Terry, I.
通讯作者：
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影响因子：
8.6
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影响因子：
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作者：
Gardner, JS;Ehlers, G;Petrovic, C
通讯作者：
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