Результаты исследований: Научные публикации в периодических изданиях › статья
Collective excitations in a two-dimensional antiferromagnet in a strong magnetic field. / Syromyatnikov, A. V.
в: Physical Review B - Condensed Matter and Materials Physics, Том 79, № 5, 2009, стр. 054413_1-6.Результаты исследований: Научные публикации в периодических изданиях › статья
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TY - JOUR
T1 - Collective excitations in a two-dimensional antiferromagnet in a strong magnetic field
AU - Syromyatnikov, A. V.
PY - 2009
Y1 - 2009
N2 - We discuss spin-1/2 two-dimensional 2D Heisenberg antiferromagnet AF on a square lattice at T=0 in strong magnetic field H near its saturation value Hc. A perturbation approach is proposed to obtain spectrum of magnons with momenta not very close to AF vector in the leading order in small parameter (Hc−H)/Hc. We find that magnons are well-defined quasiparticles at H>0.9Hc although the damping is quite large near the zone boundary. A characteristic rotonlike local minimum in the spectrum is observed at k= (\pi,\pi), accompanied by a decrease in the damping near k= (\pi,0). The suggested approach can be used in discussion of shortwavelength excitations in other 2D Bose gases of particles or quasiparticles.
AB - We discuss spin-1/2 two-dimensional 2D Heisenberg antiferromagnet AF on a square lattice at T=0 in strong magnetic field H near its saturation value Hc. A perturbation approach is proposed to obtain spectrum of magnons with momenta not very close to AF vector in the leading order in small parameter (Hc−H)/Hc. We find that magnons are well-defined quasiparticles at H>0.9Hc although the damping is quite large near the zone boundary. A characteristic rotonlike local minimum in the spectrum is observed at k= (\pi,\pi), accompanied by a decrease in the damping near k= (\pi,0). The suggested approach can be used in discussion of shortwavelength excitations in other 2D Bose gases of particles or quasiparticles.
U2 - DOI: 10.1103/PhysRevB.79.054413
DO - DOI: 10.1103/PhysRevB.79.054413
M3 - статья
VL - 79
SP - 054413_1-6
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 1098-0121
IS - 5
ER -
ID: 5083942