Dipolar antiferromagnetism and quantum criticality in LiErF₄.
Magnetism has been predicted to occur in systems in which dipolar interactions dominate exchange. We present neutron scattering, specific heat, and magnetic susceptibility data for LiErF(4), establishing it as a model dipolar-coupled antiferromagnet with planar spin-anisotropy and a quantum phase transition in applied field H(c|| = 4.0 ± 0.1 kilo-oersteds. We discovered non-mean-field critical scaling for the classical phase transition at the antiferromagnetic transition temperature that is consistent with the two-dimensional XY/h(4) universality class; in accord with this, the quantum phase transition at H(c) exhibits three-dimensional classical behavior. The effective dimensional reduction may be a consequence of the intrinsic frustrated nature of the dipolar interaction, which strengthens the role of fluctuations.
Laboratory for Quantum Magnetism, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
Conradin
C
Kraemer
Neda
N
Nikseresht
Julian O
JO
Piatek
Nikolay
N
Tsyrulin
Bastien
B
Dalla Piazza
Klaus
K
Kiefer
Bastian
B
Klemke
Thomas F
TF
Rosenbaum
Gabriel
G
Aeppli
Ché
C
Gannarelli
Karel
K
Prokes
Andrey
A
Podlesnyak
Thierry
T
Strässle
Lukas
L
Keller
Oksana
O
Zaharko
Karl W
KW
Krämer
Henrik M
HM
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