Spatially anisotropic Heisenberg kagome antiferromagnet

Abstract

We study the quasi-one-dimensional limit of the spin-1/2 quantum Heisenberg antiferromagnet on the kagome lattice. The lattice is divided into antiferromagnetic spin chains ͑exchange J͒ that are weakly coupled via intermediate "dangling" spins ͑exchange JЈ͒. Using one-dimensional bosonization, renormalization-group methods, and current algebra techniques, the ground state is determined in the limit JЈ Ӷ J. We find that the dangling spins and chain spins form a spiral with O͑1͒ and O͑JЈ / J͒ static moments, respectively, atop of which the chain spins exhibit a smaller O͓͑JЈ / J͒ 2 ͔ antiferromagnetically ordered component along the axis perpendicular to the spiral plane.with J 1 Ͻ 0 and J 2 Ͼ 0, in accordance with Eq. ͑30a͒. The estimated magnitudes of further-neighbor interactions arewhere J 3 is ferromagnetic and J 4 is antiferromagnetic. As anticipated from the RG treatment in Sec. III B, we observe SPATIALLY ANISOTROPIC HEISENBERG KAGOME… PHYSICAL REVIEW B 78, 174420 ͑2008͒ 174420-7

Ground states of spin-12triangular antiferromagnets in a magnetic field

“…This is convenient for the application of periodic boundary conditions in the TST. Many previous works on the anisotropic triangular lattice in two dimensions, including those by some of the authors 11,13 , use instead "cartesian" coordinates, as shown in in Fig. 1a.…”

“…The uniform magnetization has scaling dimension 1, whereas both the staggered spin magnetization and the staggered dimerization have scaling dimension 1/2. These three continuum operators form a closed operator algebra with well-defined operator product expansions (OPEs) used widely in literature [11][12][13][74][75][76][77] . For instance, the product of J R and N can be expanded as…”

“…(13). The function, f (x), originates from a quantum average over the normal modes of the bosonic field θ.…”

“…One is now able to fit the DMRG measurement of the transverse spinspin correlation function to Eqs. (13,14) to obtain the ordering wave vector and the additional fit parameter, η. A comparison is plotted in Fig.…”

Nuclear-Magnetic-Resonance Properties of the Staircase Kagomé Antiferromagnet PbCu 3 TeO 7

“…[1][2][3][4] . For systems with imperfect Kagomé structure, magnetic anisotropy induced by Dzyaloshinsky-Moriya (DM) interaction [5] , spatially anisotropic exchange [6] , and/or interlayer coupling may reduce geometry frustration and lead to antiferromagnetic ordering with very low Né el temperatures.…”