Finite-temperature transitions in dipolar spin ice in a large magnetic field
Finite-temperature transitions in dipolar spin ice in a large magnetic field
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DOI：
10.1103/physrevlett.95.097202
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发表时间：
2005-08-26
影响因子：
8.6
通讯作者：
Gingras, MJP
中科院分区：
文献类型：
--
作者：
Ruff, JPC;Melko, RG;Gingras, MJP
我们使用Monte Carlo模拟，以确定机制，允许在偶极自旋冰相变的发生和生存的施加磁场H的强度远大于自旋-自旋相互作用。在最一般和最高对称性的情况下，在烧绿石的四个子晶格之一上的自旋与总的局部交换+偶极+施加的场解耦。在H完全沿着[110]晶体学方向排列的特殊情况下，垂直于H的自旋链显示出向q=X长程有序的转变，这通过一维到三维的交叉进行。我们建议，这些转变是有关的起源观察到的粉末样品中的Dy 2 Ti 2 O 7自旋冰材料的H超过1特斯拉的比热特征。
We use Monte Carlo simulations to identify the mechanism that allows for phase transitions in dipolar spin ice to occur and survive for an applied magnetic field H much larger in strength than that of the spin-spin interactions. In the most generic and highest symmetry case, the spins on one out of four sublattices of the pyrochlore decouple from the total local exchange+dipolar+applied field. In the special case where H is aligned perfectly along the [110] crystallographic direction, spin chains perpendicular to H show a transition to q=X long-range order, which proceeds via a one- to three-dimensional crossover. We propose that these transitions are relevant to the origin of specific heat features observed in powder samples of the Dy2Ti2O7 spin ice material for H above 1 Tesla.