MAGNETIC RAMAN-SCATTERING FROM 1D ANTIFERROMAGNETS

Citation
Rrp. Singh et al., MAGNETIC RAMAN-SCATTERING FROM 1D ANTIFERROMAGNETS, Physical review letters, 77(19), 1996, pp. 4086-4089
Citations number
23
Categorie Soggetti
Physics
Journal title
ISSN journal
00319007
Volume
77
Issue
19
Year of publication
1996
Pages
4086 - 4089
Database
ISI
SICI code
0031-9007(1996)77:19<4086:MRF1A>2.0.ZU;2-Z
Abstract
We study Raman scattering from 1D antiferromagnets within the Fleury-L oudon scheme by applying a finite temperature Lanczos method to a 1D s pin-half Heisenberg model with nearest-neighbor (J(1)) and second-neig hbor (J(2)) interactions. The low-temperature spectra are analyzed in terms of the known elementary excitations of the system for J(2) = 0 a nd J(2) = 1/2. We find that the low-T Raman spectra are very broad for \J(2)/J(1)\ less than or equal to 0.3. This broad peak gradually dimi nishes and shifts with temperature, so that at T > J(1) the spectra ar e narrower and peaked at low frequencies. The experimental spectra for CuGeO3 are discussed in light of our calculations.