Title: Possible particle-hole instabilities in interacting type-II Weyl semimetals,
Abstract: Type II Weyl semimetal, a three dimensional gapless topological phase, has
drawn enormous interest recently. These topological semimetals enjoy overtilted
dispersion and Weyl nodes that separate the particle and hole pocket. Using
perturbation renormalization group, we identify possible renormalization of the
interaction vertices, which show a tendency toward instability. We further
adopt a self-consistent mean-field approach to study possible instability of
the type II Weyl semimetals under short-range electron-electron interaction. It
is found that the instabilities are much easier to form in type II Weyl
semimetals than the type I case. Eight different mean-field orders are
identified, among which we further show that the polar charge density wave
(CDW) phase exhibits the lowest energy. This CDW order is originated from the
nesting of the Fermi surfaces and could be a possible ground state in
interacting type II Weyl semimetals.