Modulational instability of nonlinear spin waves in easy-axis antiferromagnetic chains

被引:50
作者
Lai, R [1 ]
Sievers, AJ
机构
[1] Cornell Univ, Atom & Solid State Phys Lab, Ithaca, NY 14853 USA
[2] Cornell Univ, Ctr Mat Sci, Ithaca, NY 14853 USA
来源
PHYSICAL REVIEW B | 1998年 / 57卷 / 06期
关键词
D O I
10.1103/PhysRevB.57.3433
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The modulational instability of extended nonlinear spin waves in antiferromagnetic chains with on-site easy-axis anisotropy has been investigated both analytically in the frame of linear-stability analysis and numerically by means of molecular-dynamics simulations. The linear-stability analysis predicts the instability region and the growth rates of modulation satellites. Our numerical simulations demonstrate that the analytical predictions correctly describe the onset of instability. For long-time scales when the instability is fully developed the linear-stability analysis fails and the modulated nonlinear spin waves can evolve into localized excitations. We explore the possibility of generating intrinsic localized spin-wave modes from extended spin waves through modulational instability and find that both discreteness and strong nonlinearity seem to be essential for the creation of long-lived localized excitations. The addition of weak dissipation is found to impose a finite amplitude threshold even for infinite chains.
引用
收藏
页码:3433 / 3443
页数:11
相关论文
共 40 条
[1]   THE CONCEPT OF ANTIINTEGRABILITY APPLIED TO DYNAMICAL-SYSTEMS AND TO STRUCTURAL AND ELECTRONIC MODELS IN CONDENSED MATTER PHYSICS [J].
AUBRY, S .
PHYSICA D, 1994, 71 (1-2) :196-221
[2]   CHAOTIC TRAJECTORIES IN THE STANDARD MAP - THE CONCEPT OF ANTIINTEGRABILITY [J].
AUBRY, S ;
ABRAMOVICI, G .
PHYSICA D-NONLINEAR PHENOMENA, 1990, 43 (2-3) :199-219
[3]   Breathers in nonlinear lattices: Existence, linear stability and quantization [J].
Aubry, S .
PHYSICA D-NONLINEAR PHENOMENA, 1997, 103 (1-4) :201-250
[4]   DISINTEGRATION OF WAVE TRAINS ON DEEP WATER .1. THEORY [J].
BENJAMIN, TB ;
FEIR, JE .
JOURNAL OF FLUID MECHANICS, 1967, 27 :417-&
[5]   Energy localization in a nonlinear discrete system [J].
Bilbault, JM ;
Marquie, P .
PHYSICAL REVIEW E, 1996, 53 (05) :5403-5408
[6]   Stochastic localization [J].
Brown, DW ;
Bernstein, LJ ;
Lindenberg, K .
PHYSICAL REVIEW E, 1996, 54 (04) :3352-3360
[7]  
Burlakov V. M., 1991, Soviet Physics - JETP, V72, P854
[8]   COMPUTER-SIMULATION OF INTRINSIC LOCALIZED MODES IN ONE-DIMENSIONAL AND 2-DIMENSIONAL ANHARMONIC LATTICES [J].
BURLAKOV, VM ;
KISELEV, SA ;
PYRKOV, VN .
PHYSICAL REVIEW B, 1990, 42 (08) :4921-4927
[9]   Modulation instability and recurrence phenomena in anharmonic lattices [J].
Burlakov, VM ;
Darmanyan, SA ;
Pyrkov, VN .
PHYSICAL REVIEW B, 1996, 54 (05) :3257-3265
[10]   Modulational instability: First step towards energy localization in nonlinear lattices [J].
Daumont, I ;
Dauxois, T ;
Peyrard, M .
NONLINEARITY, 1997, 10 (03) :617-630