Abstract
We analyze an effective model on a square lattice with two types of forward scattering interactions, which, respectively, drive ferromagnetism (FM) and electronic nematic order via a -wave Pomeranchuk instability (PI). The FM and PI in general compete with each other and they are typically separated by a first-order phase boundary in the plane of the chemical potential and temperature. Nevertheless, there is a parameter region where the PI occurs inside the FM phase, leading to their coexistence. We also study the effect of a magnetic field by choosing a chemical potential where the ground state is paramagnetic without a field. In this case, instead of FM, the PI competes with a metamagnetic instability. The latter occurs above a threshold strength of the FM interaction and otherwise the PI is stabilized with a dome-shaped phase diagram in the plane of a magnetic field and temperature. The FM interaction shifts the center of the dome to a lower field, accompanied by a substantial reduction of the field range where the PI is stabilized and by an extension of the first-order part of the transition line, although the maximal critical temperature does not change. Our results indicate that proximity to the FM instability can be important to understand the experimental phase diagram observed in the bilayer ruthenate SrRuO.
1 More- Received 17 December 2012
- Publisher error corrected 17 May 2013
DOI:https://doi.org/10.1103/PhysRevB.87.195117
©2013 American Physical Society
Corrections
17 May 2013