Using Disorder to Identify Bogoliubov Fermi-Surface States

We argue that a superconducting state with a Fermi surface of Bogoliubov quasiparticles, a Bogoliubov Fermi surface (BG-FS), can be identified by the dependence of physical quantities on disorder. In particular, we show that a linear dependence of the residual density of states at weak disorder distinguishes a BG-FS state from other nodal superconducting states. We further demonstrate the stability of supercurrent against impurities and a characteristic Drude-like behavior of the optical conductivity. Our results can be directly applied to electron irradiation experiments on candidate materials of BG-FSs, including Sr2RuO4, FeSe1-xSx, and UBe13.

Automated summary

This study argues that a superconducting state with a Bogoliubov Fermi surface can be identified by the dependence of physical quantities on disorder, particularly showcasing the distinguishing linear dependence of residual density of states at weak disorder. The stability of supercurrent against impurities and characteristic Drude-like behavior of optical conductivity were also demonstrated. These findings have direct applications in electron irradiation experiments on candidate materials for Bogoliubov Fermi surfaces.