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Metamagnetic quantum criticality in Sr3Ru2O7 studied by thermal expansion

P. Gegenwart·F. Weickert·M. Garst·R. S. Perry·Y. Maeno
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Abstract

We report low-temperature thermal expansion measurements on the bilayer ruthenate Sr$_3$Ru$_2$O$_7$ 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 Tesla, 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.

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P. Gegenwart, F. Weickert, M. Garst, R. S. Perry, Y. Maeno. 2006-01-31. Metamagnetic quantum criticality in Sr3Ru2O7 studied by thermal expansion. https://doi.org/10.1103/physrevlett.96.136402

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