Unveiling a nematic quantum critical point in multi-orbital systems

TL;DR

This paper uncovers a nematic quantum critical point in multi-orbital systems, emphasizing the role of orbital degrees of freedom and explaining experimental anomalies in Sr3Ru2O7.

Contribution

It demonstrates the importance of orbital degrees of freedom in revealing a nematic QCP, which is hidden by a nearby meta-nematic transition.

Findings

Identification of a nematic quantum critical point influenced by orbital degrees of freedom

Finite temperature phase diagram including entropy landscape

Explanation of non-Fermi liquid behavior in Sr3Ru2O7

Abstract

Electronic nematicity, proposed to exist in a number of transition metal materials, can have different microscopic origins. In particular, the anisotropic resistivity and meta-magnetic jumps observed in Sr3Ru2O7 are consistent with an earlier proposal that the isotropic-nematic transition is generically first order and accompanied by meta-magnetism when tuned by a magnetic field. However, additional striking experimental features such as a non-Fermi liquid resistivity and critical thermodynamic behavior imply the presence of an unidentified quantum critical point (QCP). Here we show that orbital degrees of freedom play an essential role in revealing a nematic QCP, even though it is overshadowed by a nearby meta-nematic transition at low temperature. We further present a finite temperature phase diagram including the entropy landscape and discuss our findings in light of the phenomena observed in Sr3Ru2O7.