Theoretical realization of intrinsic ideal Weyl semimetals in spin-gapless Weyl phase of half-Heusler KCrTe

Abstract

A spin-gapless Weyl semimetal (WSM), KCrTe, is predicted by means of first-principles calculations. The novelty of spin-gapless Weyl phase is that it exhibits minimum number of Weyl points (WPs) sitting right at the Fermi level without any other trivial bands nearby. That is, KCrTe is an intrinsic ideal WSM that materials physicists have long yearned for. Regardless of the magnetization (M→), the Weyl semimetallic phase remains and the position of the WPs aligns with M→. This indicates the Fermi arc on surfaces can be tuned by an external magnetic field. Together with the spin-gapless feature, both Weyl electrons and holes with full spin polarization can be excited and their momenta can be manipulated. Our work demonstrates that KCrTe is not only the first realization of an intrinsic ideal WSM, but also a candidate for topological spin-gapless semiconductors that have great potential for the spintronic devices.

Keywords

• Ideal Weyl semimetals
• Spin-gapless semiconductors
• Topological materials
• First-principles calculations