Effect of chiral anomaly on Andreev reflection in a tilted Weyl semimetal hybrid junction

We study the influence of the chiral anomaly of a time-reversal broken Weyl semimetal on Andreev reflection in a superconductor junction. It is found that the chiral chemical potential can lead to the switching between the retro Andreev reflection (RAR) and specular Andreev reflection (SAR), which appears in both intraband and interband electron-hole conversion, violating the common rule that the intraband conversion is the RAR while the interband one is the SAR. This switching effect is dependent on the tilt of the Weyl cones and the direction of the line connecting the two Weyl points. In addition, a perfect Andreev reflection is found at the incident angle, not perpendicular to the junction interface. We also discuss the zero-bias differential conductance which provides an observable signature of the switching effect, especially for the switching between RAR and SAR caused by band transition. These findings are useful in better understanding the Andreev reflection types and detecting the chiral anomaly.