title: Metamagnetic quantum criticality in Sr3Ru2O7 studied by thermal expansion.
abstract: We report low-temperature thermal expansion measurements on the bilayer ruthenate Sr3Ru2O7 as a function of magnetic field applied perpendicular to the ruthenium-oxide planes. The field dependence of the c-axis expansion coefficient indicates the accumulation of entropy close to 8 T, related to an underlying quantum critical point. The latter is masked by two first-order metamagnetic transitions which bound a regime of enhanced entropy. Outside this region the singular thermal expansion behavior is compatible with the predictions of the itinerant theory for a two-dimensional metamagnetic quantum critical end point.
authors.affiliation: Max-Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Gegenwart
authors.forename: F
authors.initials: F
authors.lastname: Weickert
authors.forename: M
authors.initials: M
authors.lastname: Garst
authors.forename: R S
authors.initials: RS
authors.lastname: Perry
authors.forename: Y
authors.initials: Y
authors.lastname: Maeno