Vajk O P, Greven M
Department of Physics, Stanford University, Stanford, California 94305, USA.
Phys Rev Lett. 2002 Oct 21;89(17):177202. doi: 10.1103/PhysRevLett.89.177202. Epub 2002 Oct 4.
We present a numerical study of the spin-1/2 bilayer Heisenberg antiferromagnet with random interlayer dimer dilution. From the temperature dependence of the uniform susceptibility and a scaling analysis of the spin correlation length we deduce the ground state phase diagram as a function of nonmagnetic impurity concentration p and bilayer coupling g. At the site percolation threshold, there exists a multicritical point at small but nonzero bilayer coupling g(m)=0.15(3). The magnetic properties of the single-layer material La(2)Cu(1-p)(Zn,Mg)(p)O4 near the percolation threshold appear to be controlled by the proximity to this new quantum critical point.
我们对具有随机层间二聚体稀释的自旋 - 1/2双层海森堡反铁磁体进行了数值研究。从均匀磁化率的温度依赖性以及自旋关联长度的标度分析中，我们推导出了作为非磁性杂质浓度p和双层耦合g函数的基态相图。在位点渗流阈值处，在小但非零的双层耦合g(m)=0.15(3)时存在一个多临界点。接近渗流阈值的单层材料La(2)Cu(1 - p)(Zn,Mg)(p)O4的磁性似乎受接近这个新量子临界点的影响。
