论文标题
kagome抗fiferromagnets中的量子半孔
Quantum half-orphans in kagome antiferromagnets
论文作者
论文摘要
我们从数值上研究了Kagomélattice上的Spin-$ S $ HEISENBERG ANTIFERROMAGNET中非磁杂质（空位）的影响。对于一系列低但非零温度的范围，以及延伸至$ s = 2 $的自旋值，我们发现对外部磁场的磁化响应与出现的“半孔”自由度的响应是一致的，这些自由度的响应将在相似的温度范围内占据相似的经典磁力的响应，这些响应将占主导地位。具体而言，对于所有旋转值，我们已经考虑过（从$ s = 1/2 $到$ s = 4 $），在具有两个空缺的三角形上，唯一旋转的局部易感性很大。在有统一的磁场$ H $的情况下，这种孤独旋转在有效字段$ h/2 $中几乎是免费的自旋$ s $。非常值得注意的是，在零温度限制下，在半孔的存在下的基态具有非零的总旋转值$ s_ {gs} $，该趋势显示出类似于$ s/2 $当$ s \ ge 2 $时的趋势。响应的这些定性方面与没有这样一半孔自由度的稀释样品的更传统的响应明显不同。我们讨论如何通过实验检查这些发现。
We numerically study the effects of non-magnetic impurities (vacancies) in the spin-$S$ Heisenberg antiferromagnet on the kagomé lattice. For a range of low but nonzero temperatures, and spin values that extend down to $S=2$, we find that the magnetization response to an external magnetic field is consistent with the response of emergent "half-orphan" degrees of freedom that are expected to dominate the response of the corresponding classical magnet in a similar temperature range whenever there are two vacancies on the same triangle. Specifically, for all spin values we have considered (from $S=1/2$ to $S=4$), there is a large enhancement of the local susceptibility of the lone spin on such a triangle with two vacancies; in the presence of a uniform magnetic field $h$, this lone-spin behaves effectively as an almost free spin $S$ in an effective field $h/2$. Quite remarkably, in the zero temperature limit, the ground state in the presence of a half-orphan has a non-zero total spin value $S_{GS}$ that shows a trend similar to $S/2$ when $S\ge 2$. These qualitative aspects of the response differ strikingly from the more conventional response of diluted samples without such half-orphan degrees of freedom. We discuss how these findings could be checked experimentally.
