Quantum projection in an Ising spin liquid.
A transverse magnetic field is used to scan the diagonal and off-diagonal susceptibility of the uniaxial quantum magnet, LiHo(0.045) Y(0.955)F(4). Clusters of strongly coupled spins act as the primary source for the response functions, which result from a field-induced quantum projection of the system into a classically forbidden (meaning non-Ising) regime. Calculations based on spin pairs reproduce only some features of the data and fail to predict the measured off-diagonal response, providing evidence of a multispin collective state.
Silevitch
D M
DM
The James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637, USA.
Gannarelli
C M S
CM
Fisher
A J
AJ
Aeppli
G
G
Rosenbaum
T F
TF