Critical end-point and metamagnetic quantum criticality in Sr3Ru2O7

TL;DR

This paper investigates the critical end-point and quantum criticality in Sr3Ru2O7, revealing a metamagnetic critical point and unusual pressure dependence of critical parameters, contributing to understanding quantum phase transitions.

Contribution

It identifies a critical end-point in Sr3Ru2O7 and explores its pressure dependence, providing new insights into metamagnetic quantum criticality.

Findings

Critical end-point at (B*,T*)=(5.1T,1.1K) for B⊥c

First-order behavior below T* indicates a critical end-point

T* shows weak pressure dependence despite B* increasing rapidly

Abstract

We report a metamagnetic critical point at (B*,T*)=(5.1T,1.1K) for magnetic fields applied perpendicular to the (tetragonal) c-axis of Sr3Ru2O7. First-order behaviour well below T* indicates that (B*,T*) marks a critical end-point that terminates a line of first-order metamagnetic transitions. The absence of first-order behaviour in the metamagnetic transition with B||c confirms that the non-Fermi liquid behaviour for B||c is underpinned by a metamagnetic quantum critical end-point for which T*->0. Scaling behaviour of the resistivity under hydrostatic pressure yields the surprising result that although B* increases rapidly with pressure, T* has only a weak pressure dependence.