Pressure study of nematicity and quantum criticality in Sr$_3$Ru$_2$O$_7$ for an in-plane field

TL;DR

This study investigates how pressure and magnetic field orientation influence nematic phases and quantum criticality in Sr$_3$Ru$_2$O$_7$, revealing that nematicity can occur independently of metamagnetic quantum critical points.

Contribution

It demonstrates that nematic phases in Sr$_3$Ru$_2$O$_7$ can form without the presence of metamagnetic quantum criticality, challenging previous assumptions.

Findings

Nematic phase associated with QCEP when magnetic field is near c-axis at ambient pressure.

Different nematic signatures observed when QCEP is reached by pressure with in-plane field.

A second nematic phase persists under high pressure with in-plane magnetic field.

Abstract

We study the relationship between the nematic phases of Sr$_3$Ru$_2$O$_7$ and quantum criticality. At ambient pressure, one nematic phase is associated with a metamagnetic quantum critical end point (QCEP) when the applied magnetic field is near the \textit{c}-axis. We show, however, that this metamagnetic transition does not produce the same nematic signatures when the QCEP is reached by hydrostatic pressure with the field applied in the \textit{ab}-plane. Moreover, a second nematic phase, that is seen for field applied in the \textit{ab}-plane close to, but not right at, a second metamagnetic anomaly, persists with minimal change to the highest applied pressure, 16.55 kbar. Taken together our results suggest that metamagnetic quantum criticality may not be necessary for the formation of a nematic phase in Sr$_3$Ru$_2$O$_7$.