Phase Bifurcation and Quantum Fluctuations in Sr3Ru2O7

TL;DR

This paper investigates the complex magnetic and transport anomalies in Sr3Ru2O7 near its quantum critical point, proposing a magnetoelastic coupling mechanism that suggests potential quantum tricritical behavior.

Contribution

It introduces a phenomenological theory emphasizing strong magnetoelastic coupling to explain anomalous phase behavior in Sr3Ru2O7 near quantum criticality.

Findings

Anomalous magnetic and transport behavior near quantum critical point

Magnetoelastic coupling as a key mechanism

Potential for quantum tricritical phenomena

Abstract

The bilayer ruthenate Sr_3Ru_2O_7 has been cited as a textbook example of itinerant metamagnetic quantum criticality. However, recent studies of the ultra-pure system have revealed striking anomalies in magnetism and transport in the vicinity of the quantum critical point. Drawing on new experimental data, we propose that the anomalous phase behavior can be accommodated by a mechanism which relies on the effects of strong magnetoelastic coupling. We argue that the phenomenological theory identified here is more generic and raises the possibility of quantum tricritical behaviour.