Journal article
Spin excitations and quantum criticality in the quasi-one-dimensional Ising-like ferromagnet CoCl2·2D2O in a transverse field
We present experimental evidence for a quantum phase transition in the easy-axis S = 3/2 anisotropic quasione-dimensional ferromagnet CoCl2 · 2D2O in a transverse field. Elastic neutron scattering shows that the magnetic order parameter vanishes at a transverse critical field μ0Hc = 16.05(4) T, while inelastic neutron scattering shows that the gap in the magnetic excitation spectrum vanishes at the same field value, and reopens for H>Hc.
The field dependence of the order parameter and the gap are well described by critical exponents β = 0.45 ± 0.09 and zν close to 1/2, implying that the quantum phase transition in CoCl2 · 2D2O differs significantly from the textbook version of a S = 1/2 Ising chain in a transverse field. We attribute the difference to weak but finite three-dimensionality of the magnetic interactions.
Language: | English |
---|---|
Year: | 2017 |
ISSN: | 24699969 , 24699950 , 1550235x and 10980121 |
Types: | Journal article |
DOI: | 10.1103/PhysRevB.96.174424 |
ORCIDs: | 0000-0001-5270-4091 , 0000-0003-4118-5702 , 0000-0002-7954-8073 , 0000-0003-4282-756X , Ahl, Sonja Rosenlund , Toft-Petersen, Rasmus and Christensen, Niels Bech |