Fennell T, Deen P P, Wildes A R, Schmalzl K, Prabhakaran D, Boothroyd A T, Aldus R J, McMorrow D F, Bramwell S T
Institut Laue-Langevin, Grenoble 38042, France.
Science. 2009 Oct 16;326(5951):415-7. doi: 10.1126/science.1177582. Epub 2009 Sep 3.
Spin-ice materials are magnetic substances in which the spin directions map onto hydrogen positions in water ice. Their low-temperature magnetic state has been predicted to be a phase that obeys a Gauss' law and supports magnetic monopole excitations: in short, a Coulomb phase. We used polarized neutron scattering to show that the spin-ice material Ho2Ti2O7 exhibits an almost perfect Coulomb phase. Our result proves the existence of such phases in magnetic materials and strongly supports the magnetic monopole theory of spin ice.
自旋冰材料是一种磁性物质，其中自旋方向与水冰中的氢位置相对应。据预测，它们的低温磁态是一种遵循高斯定律并支持磁单极子激发的相：简而言之，是一种库仑相。我们利用极化中子散射表明，自旋冰材料Ho2Ti2O7呈现出几乎完美的库仑相。我们的结果证明了磁性材料中存在此类相，并有力地支持了自旋冰的磁单极子理论。
