Majumdar Kingshuk, Datta Trinanjan
Department of Physics, Grand Valley State University, Allendale, MI 49401, USA.
J Phys Condens Matter. 2009 Oct 7;21(40):406004. doi: 10.1088/0953-8984/21/40/406004. Epub 2009 Sep 14.
At zero temperature the sublattice magnetization of the quantum spin- 1/2 Heisenberg antiferromagnet on a body-centered cubic lattice with competing first and second neighbor exchange (J(1) and J(2)) is investigated using the non-linear spin wave theory. The zero temperature phases of the model consist of a two sublattice Néel phase for small J(2) (AF(1)) and a collinear phase at large J(2) (AF(2)). We show that quartic corrections due to spin wave interactions enhance the sublattice magnetization in both the AF(1) and the AF(2) phase. The magnetization corrections are prominent near the classical transition point of the model and in the J(2)>J(1) regime. The ground state energy with quartic interactions is also calculated. It is found that up to quartic corrections the first order phase transition (previously observed in this model) between the AF(1) and the AF(2) phase survives.
利用非线性自旋波理论，研究了具有竞争的第一和第二近邻交换（J(1)和J(2)）的体心立方晶格上量子自旋 - 1/2海森堡反铁磁体在零温度下的亚晶格磁化强度。该模型的零温度相包括小J(2)时的两子晶格奈尔相（AF(1)）和大J(2)时的共线相（AF(2)）。我们表明，由于自旋波相互作用引起的四次修正增强了AF(1)相和AF(2)相中的亚晶格磁化强度。磁化修正量在模型的经典转变点附近以及J(2)>J(1)区域中较为显著。还计算了具有四次相互作用的基态能量。结果发现，直至四次修正，AF(1)相和AF(2)相之间的一级相变（此前在该模型中已观察到）仍然存在。
