The bilayered ruthenate Sr3Ru2O7 has a metamagnetic quantum critical point. This is the first example of a material with a quantum-critical end-point. This work addresses the problem of the metamagnetic criticality in this system through the measurement of spin fluctuations by inelastic neutron scattering. Our results show that incommensurate antiferromagnetic fluctuations are present in a wide range of applied fields. We have also observed how ferromagnetic fluctuations develop at the metamagnetic field. Finally, the intensity of the two types of fluctuations is followed as a function of the energy transfer between the neutron and the spins. (C) 2007 Elsevier B.V. All rights reserved.
- inelastic neutron scattering
- quantum criticality