Quasiparticle interference in altermagnets

A novel collinear magnetic phase, termed ``altermagnetism,'' has recently been delimited, characterized by zero net magnetization and momentum-dependent collinear spin-splitting. To understand the intriguing physical effects of altermagnets and explore their potential applications, it is crucial to analyze both the geometric and spin configurations of altermagnetic Fermi surfaces. Here, we conduct a comprehensive study of the quasiparticle interference (QPI) effects induced by both nonmagnetic and magnetic impurities in metallic altermagnets, incorporating the influence of Zeeman splitting and spin-orbit coupling. By examining the QPI patterns for various spin polarizations of magnetic impurities and different spin-probe channels, we identify a series of distinctive signatures that can be used to characterize altermagnetic Fermi surfaces. These predicted signatures can be directly compared with experimental results obtained through spin-resolved scanning tunneling spectroscopy.