Physical Review B

Spin dynamics of the Ising-like fully anisotropic spin- 12 antiferromagnet in presence of a staggered magnetic field

Asim Kumar Ghosh

Published Dec 21, 2009• 7 citations

Abstract

We consider a one-dimensional Ising-like fully anisotropic $S=\frac{1}{2}$ Heisenberg antiferromagnetic Hamiltonian and study the dynamics of domain-wall excitations in the presence of a staggered magnetic field, ${h}_{x}$, along the transverse direction. We obtain dynamical spin-correlation functions along the magnetic field, ${S}^{xx}(q,\ensuremath{\omega})$, and perpendicular to it, ${S}^{yy}(q,\ensuremath{\omega})$. It is shown that the line shapes of ${S}^{xx}(q,\ensuremath{\omega})$ and ${S}^{yy}(q,\ensuremath{\omega})$ are purely symmetric at the zone boundary, $q=\frac{\ensuremath{\pi}}{2}$. It is observed in ${S}^{xx}(q,\ensuremath{\omega})$ for $\ensuremath{\pi}/2<q<\ensuremath{\pi}$ that the spectral weight moves toward high-energy side with the increase in ${h}_{x}$. We discuss the relevance of this model to explain the spin dynamics of ${\text{CsCoCl}}_{3}$ in presence of weak staggered field.

DOI: 10.1103/physrevb.80.214418

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Spin dynamics of a one-dimensional spin-1/2 fully anisotropic Ising-like antiferromagnet in a transverse magnetic field

Asimkumar Ghosh

arXiv:cond-mat/0109364Journal of Physics Condensed MatterMay 18, 20016 citations

Spin Dynamics of a One Dimensional Ising-Like Antiferromagnet in a Transverse Magnetic Field

Kohei Murao, Fumitaka Matsubara, Sakari Inawashiro

Journal of the Physical Society of JapanJan 15, 19954 citations

Kink confinement in the antiferromagnetic XXZ spin-(1/2) chain in a weak staggered magnetic field

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Domain-Wall Excitations in an Ising-Like Antiferromagnetic Chain under a Transverse Magnetic Field

Shigeyoshi Mori, Isao Mannari, Isao Harada

Journal of the Physical Society of JapanSep 15, 199411 citations

Low-energy properties of anisotropic two-dimensional spin- 12 Heisenberg models in staggered magnetic fields

Bin Xi, Shijie Hu, Jize Zhao +3 more

arXiv:1106.4605Physical Review BOct 10, 201111 citations

Dynamical correlations of the spin- 12 Heisenberg XXZ chain in a staggered field

Igor Kuzmenko, Fabian H. L. Eßler

arXiv:0809.0398Physical Review BJan 5, 200915 citations

Physical Review B

Spin dynamics of the Ising-like fully anisotropic spin- 12 antiferromagnet in presence of a staggered magnetic field

Asim Kumar Ghosh

Published Dec 21, 2009• 7 citations

Publisher

Abstract

We consider a one-dimensional Ising-like fully anisotropic

S=\frac{1}{2}

Heisenberg antiferromagnetic Hamiltonian and study the dynamics of domain-wall excitations in the presence of a staggered magnetic field,

{h}_{x}

, along the transverse direction. We obtain dynamical spin-correlation functions along the magnetic field,

{S}^{xx}(q,\ensuremath{\omega})

, and perpendicular to it,

{S}^{yy}(q,\ensuremath{\omega})

. It is shown that the line shapes of

{S}^{xx}(q,\ensuremath{\omega})

and

{S}^{yy}(q,\ensuremath{\omega})

are purely symmetric at the zone boundary,

q=\frac{\ensuremath{\pi}}{2}

. It is observed in

{S}^{xx}(q,\ensuremath{\omega})

for

\ensuremath{\pi}/2<q<\ensuremath{\pi}

that the spectral weight moves toward high-energy side with the increase in

{h}_{x}

. We discuss the relevance of this model to explain the spin dynamics of

{\text{CsCoCl}}_{3}

in presence of weak staggered field.

DOI: 10.1103/physrevb.80.214418

Related papers

Spin dynamics of a one-dimensional spin-1/2 fully anisotropic Ising-like antiferromagnet in a transverse magnetic field

Asimkumar Ghosh

We consider the one-dimensional Ising-like fully anisotropic S = 1/2 Heisenberg antiferromagnetic Hamiltonian and study the dynamics of domain wall excitations in the presence of a transverse magnetic field h x . We obtain dynamical spin correlation functions along the magnetic field, S xx ( q ,ω), and perpendicular to it, S yy ( q ,ω). It is shown that the line shapes of S xx ( q ,ω) and S yy ( q ,ω) are purely symmetric at the zone boundary. It is observed in S yy ( q ,ω) for π/2< q <π that the spectral weight moves toward the low-energy side with the increase of h x . This model is applicable to the study of the spin dynamics of CsCoCl 3 in the presence of weak interchain interactions.We consider the one-dimensional Ising-like fully anisotropic S = 1/2 Heisenberg antiferromagnetic Hamiltonian and study the dynamics of domain wall excitations in the presence of a transverse magnetic field h x . We obtain dynamical spin correlation functions along the magnetic field, S xx ( q ,ω), and perpendicular to it, S yy ( q ,ω). It is shown that the line shapes of S xx ( q ,ω) and S yy ( q ,ω) are purely symmetric at the zone boundary. It is observed in S yy ( q ,ω) for π/2< q <π that the spectral weight moves toward the low-energy side with the increase of h x . This model is applicable to the study of the spin dynamics of CsCoCl 3 in the presence of weak interchain interactions.

arXiv:cond-mat/0109364Journal of Physics Condensed MatterMay 18, 20016 citations

Spin Dynamics of a One Dimensional Ising-Like Antiferromagnet in a Transverse Magnetic Field

Kohei Murao, Fumitaka Matsubara, Sakari Inawashiro

The effect of the transverse magnetic field h x on the spin dynamics of a one dimensional Ising-like S =1/2 antiferromagnet is discussed. Based on a picture of the propagating domain walls, we obtain dynamical spin correlation functions along the magnetic field S x x ( k ,ω) and perpendicular to it S y y ( k ,ω). A remarkable effect is seen in S y y ( k ,ω) for π/2 ≤ k ≤π, where the spectral weight moves toward the low energy side with the increase of h x . The theory is applied to the analysis of the spin dynamics of CsCoCl 3 , taking into account weak interchain interactions. Zeeman ladders occur and S y y ( k , ω) for k ∼π exhibits a novel feature under the existence of h x .The effect of the transverse magnetic field h x on the spin dynamics of a one dimensional Ising-like S =1/2 antiferromagnet is discussed. Based on a picture of the propagating domain walls, we obtain dynamical spin correlation functions along the magnetic field S x x ( k ,ω) and perpendicular to it S y y ( k ,ω). A remarkable effect is seen in S y y ( k ,ω) for π/2 ≤ k ≤π, where the spectral weight moves toward the low energy side with the increase of h x . The theory is applied to the analysis of the spin dynamics of CsCoCl 3 , taking into account weak interchain interactions. Zeeman ladders occur and S y y ( k , ω) for k ∼π exhibits a novel feature under the existence of h x .

Journal of the Physical Society of JapanJan 15, 19954 citations

Kink confinement in the antiferromagnetic XXZ spin-(1/2) chain in a weak staggered magnetic field

S. B. Rutkevich

The Heisenberg XXZ spin-(1/2) chain is considered in the massive antiferromagnetic regime in the presence of a staggered longitudinal magnetic field. The Hamiltonian of the model is characterised by the anisotropy parameter and by the magnetic-field strength h . At zero magnetic field, the model is exactly solvable. In the thermodynamic limit, it has two degenerate vacua and the kinks (which are also called spinons) interpolating between these vacua, as elementary excitations. Application of the staggered magnetic field breaks integrability of the model and induces the long-range attractive potential between two adjacent kinks leading to their confinement into the bound states. The energy spectra of the resulting two-kink bound states are perturbatively calculated in the extreme anisotropic (Ising) limit to the first order in the inverse anisotropy constant , and also for any to the first order in the weak magnetic field h .The Heisenberg XXZ spin-(1/2) chain is considered in the massive antiferromagnetic regime in the presence of a staggered longitudinal magnetic field. The Hamiltonian of the model is characterised by the anisotropy parameter and by the magnetic-field strength h . At zero magnetic field, the model is exactly solvable. In the thermodynamic limit, it has two degenerate vacua and the kinks (which are also called spinons) interpolating between these vacua, as elementary excitations. Application of the staggered magnetic field breaks integrability of the model and induces the long-range attractive potential between two adjacent kinks leading to their confinement into the bound states. The energy spectra of the resulting two-kink bound states are perturbatively calculated in the extreme anisotropic (Ising) limit to the first order in the inverse anisotropy constant , and also for any to the first order in the weak magnetic field h .

arXiv:1710.11605Europhysics Letters (EPL)Feb 1, 201816 citations

Domain-Wall Excitations in an Ising-Like Antiferromagnetic Chain under a Transverse Magnetic Field

Shigeyoshi Mori, Isao Mannari, Isao Harada

We study effects of a transverse magnetic field on the properties of the one-dimensional spin-1/2 Ising-like antiferromagnet. In order to emphasize the relevant role of domain walls between opposite antiferromagnetic domains, the spin Hamiltonian is exactly mapped to the interacting fermion Hamiltonian, via the dual transformation as well as the Jordan-Wigner transformation. Within the generalized Hartree-Fock approximation, we find that the excitation spectrum exhibits characteristic features, which are explained as a result of the different roles of the transverse field and of the transverse components of the exchange interactions in the propagation of the domain wall. At a critical field where the excitation gap vanishes, a ground-state phase transition is found to take place in the same manner as that in the transverse Ising model. In addition, we discuss the relevance of our magnetization curve with regard to experimental data in CsCoCl 3 .We study effects of a transverse magnetic field on the properties of the one-dimensional spin-1/2 Ising-like antiferromagnet. In order to emphasize the relevant role of domain walls between opposite antiferromagnetic domains, the spin Hamiltonian is exactly mapped to the interacting fermion Hamiltonian, via the dual transformation as well as the Jordan-Wigner transformation. Within the generalized Hartree-Fock approximation, we find that the excitation spectrum exhibits characteristic features, which are explained as a result of the different roles of the transverse field and of the transverse components of the exchange interactions in the propagation of the domain wall. At a critical field where the excitation gap vanishes, a ground-state phase transition is found to take place in the same manner as that in the transverse Ising model. In addition, we discuss the relevance of our magnetization curve with regard to experimental data in CsCoCl 3 .

Journal of the Physical Society of JapanSep 15, 199411 citations

Low-energy properties of anisotropic two-dimensional spin- 12 Heisenberg models in staggered magnetic fields

Bin Xi, Shijie Hu, Jize Zhao +3 more

We present a systematic study of the anisotropic spin-1/2 Heisenberg model in staggered magnetic fields in two dimensions. To mimic real materials, we consider a system of coupled, antiferromagnetic chains, whose interchain interaction can be either ferro- or antiferromagnetic. When the staggered field is commensurate with the magnetic interactions, an energy gap opens immediately and follows a power law as a function of the applied field, similar to the situation in one dimension. When the field competes with the interactions, a quantum phase transition (QPT) occurs from a gapless, magnetically ordered phase at low fields to a gapped, disordered regime. We use a continuous-time Monte Carlo method to compute the staggered moment of the ordered phases and the spin gap of the disordered phases. We deduce the phase diagrams as functions of the anisotropy ratio and the applied field, and calculate the scaling behavior of the models in both quantities. We show that in the competitive case, the staggered field acts to maintain a regime of quasi-1D behavior around the QPT, and we discuss as a consequence the nature of the crossover from one-dimensional (1D) to 2D physics.We present a systematic study of the anisotropic spin-1/2 Heisenberg model in staggered magnetic fields in two dimensions. To mimic real materials, we consider a system of coupled, antiferromagnetic chains, whose interchain interaction can be either ferro- or antiferromagnetic. When the staggered field is commensurate with the magnetic interactions, an energy gap opens immediately and follows a power law as a function of the applied field, similar to the situation in one dimension. When the field competes with the interactions, a quantum phase transition (QPT) occurs from a gapless, magnetically ordered phase at low fields to a gapped, disordered regime. We use a continuous-time Monte Carlo method to compute the staggered moment of the ordered phases and the spin gap of the disordered phases. We deduce the phase diagrams as functions of the anisotropy ratio and the applied field, and calculate the scaling behavior of the models in both quantities. We show that in the competitive case, the staggered field acts to maintain a regime of quasi-1D behavior around the QPT, and we discuss as a consequence the nature of the crossover from one-dimensional (1D) to 2D physics.

arXiv:1106.4605Physical Review BOct 10, 201111 citations

Dynamical correlations of the spin- 12 Heisenberg XXZ chain in a staggered field

Igor Kuzmenko, Fabian H. L. Eßler

We consider the easy-plane anisotropic spin- $\frac{1}{2}$ Heisenberg chain in combined uniform longitudinal and transverse staggered magnetic fields. The low-energy limit of his model is described by the sine-Gordon quantum field theory. Using methods of integrable quantum field theory we determine the various components of the dynamical structure factor. To do so, we derive explicit expressions for all matrix elements of the low-energy projections of the spin operators involving at most two particles. We discuss applications of our results to experiments on one-dimensional quantum magnets.We consider the easy-plane anisotropic spin-$\frac{1}{2}$ Heisenberg chain in combined uniform longitudinal and transverse staggered magnetic fields. The low-energy limit of his model is described by the sine-Gordon quantum field theory. Using methods of integrable quantum field theory we determine the various components of the dynamical structure factor. To do so, we derive explicit expressions for all matrix elements of the low-energy projections of the spin operators involving at most two particles. We discuss applications of our results to experiments on one-dimensional quantum magnets.

arXiv:0809.0398Physical Review BJan 5, 200915 citations

We consider a one-dimensional Ising-like fully anisotropic

S=\frac{1}{2}

Heisenberg antiferromagnetic Hamiltonian and study the dynamics of domain-wall excitations in the presence of a staggered magnetic field,

{h}_{x}

, along the transverse direction. We obtain dynamical spin-correlation functions along the magnetic field,

{S}^{xx}(q,\ensuremath{\omega})

, and perpendicular to it,

{S}^{yy}(q,\ensuremath{\omega})

. It is shown that the line shapes of

{S}^{xx}(q,\ensuremath{\omega})

and

{S}^{yy}(q,\ensuremath{\omega})

are purely symmetric at the zone boundary,

q=\frac{\ensuremath{\pi}}{2}

. It is observed in

{S}^{xx}(q,\ensuremath{\omega})

for

\ensuremath{\pi}/2<q<\ensuremath{\pi}

that the spectral weight moves toward high-energy side with the increase in

{h}_{x}

. We discuss the relevance of this model to explain the spin dynamics of

{\text{CsCoCl}}_{3}

in presence of weak staggered field.

We consider the easy-plane anisotropic spin-

\frac{1}{2}

Heisenberg chain in combined uniform longitudinal and transverse staggered magnetic fields. The low-energy limit of his model is described by the sine-Gordon quantum field theory. Using methods of integrable quantum field theory we determine the various components of the dynamical structure factor. To do so, we derive explicit expressions for all matrix elements of the low-energy projections of the spin operators involving at most two particles. We discuss applications of our results to experiments on one-dimensional quantum magnets.