Anomalous Behavior of the Magnetization Process of the S = 1/2 Kagome-Lattice Heisenberg Antiferromagnet at One-Third Height of the Saturation

Abstract

The magnetization process of the S = 1/2 Heisenberg antiferromagnet on the kagome lattice is studied by the numerical-diagonalization method. We successfully obtain a new result of the magnetization process of a 42-site cluster in the entire range. Our analysis clarifies that the critical behavior around one-third of the height of the saturation is different from the typical behavior of the well-known magnetization plateau in two-dimensional systems. We also examine the effect of the √ 3 × √ 3-type distortion added to the kagome lattice. We find at one-third of the height of the saturation in the magnetization process that the undistorted kagome point is just the boundary between two phases that show their own properties that are different from each other. Our results suggest a relationship between the anomalous critical behavior at the undistorted point and the fact that the undistorted point is the boundary.

Magnetization Process of the Spin-S Kagome-Lattice Heisenberg Antiferromagnet

“…In the case of S = 1/2, the m = 1/3 state of several frustrated systems shows an interesting phase transition between the ferrimagnetic state and another state accompanied by a novel spin-flop phenomenon. 27,[50][51][52][53]62 One of the cases is when the kagome lattice is distorted to the √ 3 × √ 3 type. 27 Future studies taking this distortion into account could help us to more clearly estabish the relationship between the nine-site structure pointed out in Ref.…”

“…27,[50][51][52][53]62 One of the cases is when the kagome lattice is distorted to the √ 3 × √ 3 type. 27 Future studies taking this distortion into account could help us to more clearly estabish the relationship between the nine-site structure pointed out in Ref. 42 and unbiased numerical data.…”

“…45 The usefulness of our program was previously confirmed in large-scale parallelized calculations. 19,27,46 The magnetization process for a finite-size system is obtained by considering the magnetization increase from M to M + 1 in the fieldunder the condition that the lowest-energy state with magnetization M and that with magnetization M + 1 become the ground state in specific magnetic fields. First, let us present our results of the magnetization processes for S = 1, 3/2, 2, and 5/2; results are shown in Fig.…”

“…45 The usefulness of our program was previously confirmed in large-scale parallelized calculations. 19,27,46 The magnetization process for a finite-size system is obtained by considering the magnetization increase from M to M + 1 in the field…”

Instability of a ferrimagnetic state of a frustratedS= 1/2 Heisenberg antiferromagnet in two dimensions

“…22) Note here that our program was effectively used in large-scale parallelized calculations. [23][24][25] To obtain the magnetization process for a finite-size system, one finds the magnetization increase from M to M + 1 at the field…”