Citation
S. Raymond et al., Polarized-neutron observation of longitudinal haldane-gap excitations in Nd2BaNiO5, PHYS REV L, 82(11), 1999, pp. 2382-2385
Citations number
24
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW LETTERS
ISSN journal
00319007
→ ACNP
Volume
82
Issue
11
Year of publication
1999
Pages
2382 - 2385
Database
ISI
SICI code
0031-9007(19990315)82:11<2382:POOLHE>2.0.ZU;2-X
Abstract
Polarized and unpolarized inelastic neutron scattering is used to study Hal
dane-gap excitations in the mixed-spin linear-chain antiferromagnet Nd2BaNi
O5. The longitudinal mode, polarized along the direction of ordered moments
, is observed for the first time. The model of isolated Haldane chains in a
static staggered exchange field, that is known to work very well for stati
c properties and transverse spin excitations in R2BaNiO5 compounds, fails t
o explain new results for the longitudinal spin gap.