arXiv:cond-mat/0608582 · Journal of Physics Condensed Matter

Ferrimagnetic states inS= 1/2 frustrated Heisenberg chains with period 3 exchange modulation

K Hida

Published Mar 23, 2007• 25 citations

Abstract

The ground state properties of the S = 1/2 frustrated Heisenberg chain with period 3 exchange modulation are investigated using the numerical diagonalization and density matrix renormalization group (DMRG) method. It is known that this model has a magnetization plateau at one third of the saturation magnetization M s . On the other hand, the ground state is ferrimagnetic even in the absence of frustration if one of the nearest neighbour bond is ferromagnetic and the others are antiferromagnetic. In the present work, we show that this ferrimagnetic state continues to the region in which all bonds are antiferromagnetic if the frustration is strong. This state further continues to the above-mentioned 1/3 plateau state. In between, we also find the noncollinear ferrimagnetic phase in which the spontaneous magnetization is finite but less than M s /3. The intuitive interpretation for the phase diagram is given and the physical properties of these phases are discussed.

DOI: 10.1088/0953-8984/19/14/145225

Related papers

Ferrimagnetic states in S=1/2 frustrated Heisenberg chains with period 3 exchange modulation

和男飛田

The ground state properties of the S = 1/ 2 frustrated Heisenberg chain with period 3 exchange modulation are investigated using the numerical diagonalization and density matrix renormalization group (DMRG) method. It is known that this model has a magnetization plateau at one third of the saturation magnetization Ms. On the other hand, the ground state is ferrimagnetic even in the absence of frustration if one of the nearest neighbour bond is ferromagnetic and the others are antiferromagnetic. In the present work, we show that this ferrimagnetic state continues to the region in which all bonds are antiferromagnetic if the frustration is strong. This state further continues to the above- mentioned 1/ 3 plateau state. In between, we also find the noncollinear ferrimagnetic phase in which the spontaneous magnetization is finite but less than Ms/ 3. The intuitive interpretation for the phase diagram is given and the physical properties of these phases are discussed.

Journal of Physics Condensed MatterApr 1, 20070 citations

Frustration-Induced Ferrimagnetism inS= 1/2 Heisenberg Spin Chain

Tokuro Shimokawa, Hiroki Nakano

The ground-state properties of the S=1/2 frustrated Heisenberg spin chain with interactions up to fourth nearest neighbors are investigated by the exact-diagonalization method and density matrix renormalization group method. Our numerical calculations clarify that the ferrimagnetic state is realized in the ground state in spite of the fact that a multi-sublattice structure in the shape of the system is absent. We find that there are two types of ferrimagnetic phases: one is the well-known ferrimagnetic phase of the Lieb-Mattis type and the other is the nontrivial ferrimagnetic phase that is different from that of the Lieb-Mattis type. Our results suggest that a multi-sublattice structure of the shape is not necessarily required for the occurrence of ferrimagnetism.

arXiv:1102.4414Journal of the Physical Society of JapanMar 29, 201121 citations

Ferrimagnetic and long period antiferromagnetic phases in high spin Heisenberg chains with D-modulation

和男飛田

The ground state properties of the high spin Heisenberg chains with alternating single site anisotropy are investigated by means of the numerical exact daigonaization and DMRG method.It is found that the ferrimagnetic state appears between the Haldane phase and period doubled Néel phase for the integer spin chains.On the other hand, the transition from the Tomonaga-Luttinger liquid state into the ferrimagnetic state takes place for the half-odd-integer spin chains.In the ferrimagnetic phase, the spontaneous magnetization varies continuously with the modulation amplitude of the single site anisotropy.Eventually, the magnetization is locked to fractional values of the saturated magnetization.These fractional values satisfy the Oshikawa-Yamanaka-Affleck condition.The local spin profile is calculated to reveal the physical nature of each state.In contrast to the case of frustration induced ferrimagnetism, no incommensurate magnetic superstructure is found.

Journal of the Physical Society of JapanJan 1, 20070 citations

Ferrimagnetic and Long Period Antiferromagnetic Phases in High Spin Heisenberg Chains with D-Modulation

Kazuo Hida

The ground state properties of the high spin Heisenberg chains with alternating single site anisotropy are investigated by means of the numerical exact daigonaization and DMRG method. It is found that the ferrimagnetic state appears between the Haldane phase and period doubled Néel phase for the integer spin chains. On the other hand, the transition from the Tomonaga-Luttinger liquid state into the ferrimagnetic state takes place for the half-odd-integer spin chains. In the ferrimagnetic phase, the spontaneous magnetization varies continuously with the modulation amplitude of the single site anisotropy. Eventually, the magnetization is locked to fractional values of the saturated magnetization. These fractional values satisfy the Oshikawa-Yamanaka-Affleck condition. The local spin profile is calculated to reveal the physical nature of each state. In contrast to the case of frustration induced ferrimagnetism, no incommensurate magnetic superstructure is found.

arXiv:cond-mat/0610660Journal of the Physical Society of JapanFeb 13, 200712 citations

Quantum vs Classical Magnetization Plateaus of S=1/2 Frustrated Heisenberg Chains

Kazuo Hida, Ian K. Affleck

The competition between quantum and classical magnetization plateaus of S=1/2 frustrated Heisenberg chains with modified exchange couplings is investigated. The conventional S=1/2 frustrated Heisenberg chains is known to exhibit a 3-fold degenerate udu-type classical plateau at 1/3 of the saturation magnetization accompanied by the spontaneous Z_3 translational symmetry breakdown. The stability of this plateau phase against period 3 exchange modulation which favors the 00u-type quantum plateau state (00= singlet dimer) is studied by bosonization, renormalization group and numerical diagonalization methods. The ground state phase diagram and the spin configuration in each phase are numerically determined. The translationally invariant Valence Bond Solid-type model with 4-spin and third neighbor interactions, which has the exact 00u-type quantum plateau state, is also presented. The phase transition to the classical udu-type ground state is also observed by varying the strength of 4-spin and third neighbor interactions. The relation between these two types of models with quantum plateau states is discussed.

arXiv:cond-mat/0501697Journal of the Physical Society of JapanJun 1, 200546 citations

Quantum phase transition as a result of magnetic frustrations in a ferrimagnetic Heisenberg system

Zhang Song-Jun, Jianjun Jiang, Yongjun Liu +1 more

Using density-matrix renormalization group (DMRG) method, we studied the effect of magnetic frustrations due to next-nearest- neighbor bonds in a system of quasi-one-dimensional Heisenberg antiferromagnetic chain but with ferrimagnetic properties. In this paper, the ground state energy per unit cell, spin correlation function and spin gap are calculated. As a result of the frustrations, the quantum disordered phase with the spin gap appears at the spin order-disorder phase transition point αC≈0.412 to α＝1. And in the region of magnetic-order phase, the increasing magnetic frustrations reduce the magnetic order.

Acta Physica SinicaJan 1, 20085 citations