Research output: Contribution to journal › Article
Spectrum of short-wavelength magnons in two-dimensional quantum Heisenberg antiferromagnet on a square lattice: third order expansion in 1/S. / Syromyatnikov, A. V.
In: Journal of Physics: Condensed Matter, Vol. 22, No. 21, 2010, p. 216003_1-7.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Spectrum of short-wavelength magnons in two-dimensional quantum Heisenberg antiferromagnet on a square lattice: third order expansion in 1/S
AU - Syromyatnikov, A. V.
PY - 2010
Y1 - 2010
N2 - The spectrum of short-wavelength magnons in two-dimensional quantum Heisenberg antiferromagnet on a square lattice is calculated in the third order in $1/S$ expansion. It is shown that $1/S$ series for $S=1/2$ converges fast in the whole Brillouin zone except for the neighborhood of the point ${\bf k}=(\pi,0)$, at which absolute values of the third and the second order $1/S$-corrections are approximately equal to each other. It is shown that the third order corrections make deeper the roton-like local minimum at ${\bf k}=(\pi,0)$ improving the agreement with the recent experiments and numerical results in the neighborhood of this point. It is suggested that $1/S$ series converges slowly near ${\bf k}=(\pi,0)$ also for $S=1$ although the spectrum renormalization would be small in this case due to very small values of high-order $1/S$ corrections.
AB - The spectrum of short-wavelength magnons in two-dimensional quantum Heisenberg antiferromagnet on a square lattice is calculated in the third order in $1/S$ expansion. It is shown that $1/S$ series for $S=1/2$ converges fast in the whole Brillouin zone except for the neighborhood of the point ${\bf k}=(\pi,0)$, at which absolute values of the third and the second order $1/S$-corrections are approximately equal to each other. It is shown that the third order corrections make deeper the roton-like local minimum at ${\bf k}=(\pi,0)$ improving the agreement with the recent experiments and numerical results in the neighborhood of this point. It is suggested that $1/S$ series converges slowly near ${\bf k}=(\pi,0)$ also for $S=1$ although the spectrum renormalization would be small in this case due to very small values of high-order $1/S$ corrections.
U2 - doi:10.1088/0953-8984/22/21/216003
DO - doi:10.1088/0953-8984/22/21/216003
M3 - статья
VL - 22
SP - 216003_1-7
JO - Journal of Physics Condensed Matter
JF - Journal of Physics Condensed Matter
SN - 0953-8984
IS - 21
ER -
ID: 5084315