Budnik Ran, Auerbach Assa
Physics Department, Technion, Haifa 32000, Israel.
Phys Rev Lett. 2004 Oct 29;93(18):187205. doi: 10.1103/PhysRevLett.93.187205.
The spin-1/2 Heisenberg antiferromagnet on the kagomé lattice, is mapped by contractor renormalization to a spin-pseudospin Hamiltonian on the triangular superlattice. Variationally, we find a ground state with columnar dimer order. Dimer orientation fluctuations are described by an effective O(2) model at energies above an exponentially suppressed clock mass scale. Our results explain the large density of low-energy singlets observed numerically, and the nonmagnetic T2 specific heat observed experimentally.
kagomé晶格上的自旋1/2海森堡反铁磁体，通过收缩重整化映射到三角超晶格上的自旋-赝自旋哈密顿量。通过变分法，我们发现了具有柱状二聚体序的基态。在能量高于指数抑制的时钟质量标度时，二聚体取向涨落由一个有效的O(2)模型描述。我们的结果解释了数值上观测到的低能单重态的高态密度，以及实验上观测到的非磁性T2比热。
