Spin dynamics of the 2D spin 1/2 quantum antiferromagnet copper deuteroformate tetradeuterate (CFTD).
The magnetic excitation spectrum in the two-dimensional (2D) S = 1/2 Heisenberg antiferromagnet copper deuteroformate tetradeuterate has been measured for temperatures up to T approximately J/2, where J = 6.31+/-0.02 meV is the 2D exchange coupling. For T<<J, a dispersion of the zone boundary energy is observed, which is attributed to a wave vector dependent quantum renormalization. At higher temperatures, spin-wavelike excitations persist, but are found to broaden and soften. By combining our data with numerical calculations, and with existing theoretical work, a consistent description of the behavior of the model system is found over the whole temperature interval investigated.
Rønnow
H M
HM
Condensed Matter Physics and Chemistry Department, Risø National Laboratory, DK-4000 Roskilde, Denmark.
McMorrow
D F
DF
Coldea
R
R
Harrison
A
A
Youngson
I D
ID
Perring
T G
TG
Aeppli
G
G
Syljuåsen
O
O
Lefmann
K
K
Rischel
C
C