a Microscopic Calculation of the Dynamical Correlation Functions of the One and Two Dimensional Quantum Heisenberg Antiferromagnet

We present low-temperature dynamic properties of the quantum two-dimensional antiferromagnetic Heisenberg model with spin $S=1∕2$ . The calculation of the dynamic correlation function is performed by combining a projection operator formalism and the modified spin-wave theory, which gives a gap in the dispersion relation for finite temperatures. The so calculated dynamic correlation function shows a double peak structure. We also obtain the spin-wave damping and compare our results to some experimental data and theoretical results obtained by other authors using different approaches.We present low-temperature dynamic properties of the quantum two-dimensional antiferromagnetic Heisenberg model with spin $S=1∕2$. The calculation of the dynamic correlation function is performed by combining a projection operator formalism and the modified spin-wave theory, which gives a gap in the dispersion relation for finite temperatures. The so calculated dynamic correlation function shows a double peak structure. We also obtain the spin-wave damping and compare our results to some experimental data and theoretical results obtained by other authors using different approaches.

arXiv:cond-mat/0505458Physical Review BNov 22, 200514 citations

Dynamical properties of quantum antiferromagnets in one and two dimensions

Chiranjeeb Buragohain

Jan 1, 20010 citations

Simple quantum model for correlations in random one-dimensional Heisenberg antiferromagnets

Hans A. De Raedt, Ad Lagendijk

Using a simple quantum model we calculate static correlations for the random $S=\frac{1}{2}$ Heisenberg antiferromagnets. The correlations decay exponentially with distance. In addition the second moment of a two-spin correlation function was evaluated. No agreement with experiment could be obtained when we tried to extract the correlation time of this correlation function from its second moment.Using a simple quantum model we calculate static correlations for the random $S=\frac{1}{2}$ Heisenberg antiferromagnets. The correlations decay exponentially with distance. In addition the second moment of a two-spin correlation function was evaluated. No agreement with experiment could be obtained when we tried to extract the correlation time of this correlation function from its second moment.

Physical review. B, Condensed matterJul 1, 19814 citations

Finite-temperature correlation functions of Heisenberg antiferromagnet

Anatoli G. Izergin, V. E. Korepin, N. A. Slavnov

Theoretical and Mathematical PhysicsAug 1, 19877 citations

Estudo da dinâmica de alguns modelos antiferromagnéticos unidimensionais.

L.S. Lima

We present the low-temperature dynamic properties of the quantum one-dimensional Heisenberg antiferromagnet with integer Spin S with spin-phonon interaction, Dzyaloshins-kii-Moriya interaction and taking into account three magnon processes. First, we present the low-temperature dynamic properties of the quantum one-dimensionalHeisenberg antiferromagnet with integer spin S coupled to phonons. The calculation of the relaxation function is performed using the combination of the memory function formalism with the modified spin-wave theory. The procedure includes up to two-magnon and magnon-phonon processes. We show that the magnon-phonon coupling smooths the double-peak structure obtained for the model in the absence of phonons, when the wavevector q moves from q = ¼. After that, we present a calculation of the in-plane dynamical structure factor for the S = 1 one-dimensional antiferromagnet with a Dzyaloshinskii-Moriya interaction using the Schwinger boson mean-field theory. Then, we present the dynamical properties of the Heisenberg antiferromagnet takinginto account three magnon processes. We calculate the correlation function in time using the modified spin-wave theory. The procedure here includes up to two and three-magnon processes. We show that the double peak structure obtained for the model taking into account two-magnon processes is not smoothed when we take account three-magnon processes tooWe present the low-temperature dynamic properties of the quantum one-dimensional Heisenberg antiferromagnet with integer Spin S with spin-phonon interaction, Dzyaloshins-kii-Moriya interaction and taking into account three magnon processes. First, we present the low-temperature dynamic properties of the quantum one-dimensionalHeisenberg antiferromagnet with integer spin S coupled to phonons. The calculation of the relaxation function is performed using the combination of the memory function formalism with the modified spin-wave theory. The procedure includes up to two-magnon and magnon-phonon processes. We show that the magnon-phonon coupling smooths the double-peak structure obtained for the model in the absence of phonons, when the wavevector q moves from q = ¼. After that, we present a calculation of the in-plane dynamical structure factor for the S = 1 one-dimensional antiferromagnet with a Dzyaloshinskii-Moriya interaction using the Schwinger boson mean-field theory. Then, we present the dynamical properties of the Heisenberg antiferromagnet takinginto account three magnon processes. We calculate the correlation function in time using the modified spin-wave theory. The procedure here includes up to two and three-magnon processes. We show that the double peak structure obtained for the model taking into account two-magnon processes is not smoothed when we take account three-magnon processes too

Mar 2, 20090 citations

We present low-temperature dynamic properties of the quantum two-dimensional antiferromagnetic Heisenberg model with spin

S=1∕2

. The calculation of the dynamic correlation function is performed by combining a projection operator formalism and the modified spin-wave theory, which gives a gap in the dispersion relation for finite temperatures. The so calculated dynamic correlation function shows a double peak structure. We also obtain the spin-wave damping and compare our results to some experimental data and theoretical results obtained by other authors using different approaches.

Using a simple quantum model we calculate static correlations for the random

S=\frac{1}{2}

Heisenberg antiferromagnets. The correlations decay exponentially with distance. In addition the second moment of a two-spin correlation function was evaluated. No agreement with experiment could be obtained when we tried to extract the correlation time of this correlation function from its second moment.