title: Acoustic Type-II Weyl Nodes from Stacking Dimerized Chains.
abstract: Lorentz-violating type-II Weyl fermions, which were missed in Weyl's prediction of nowadays classified type-I Weyl fermions in quantum field theory, have recently been proposed in condensed matter systems. The semimetals hosting type-II Weyl fermions offer a rare platform for realizing many exotic physical phenomena that are different from type-I Weyl systems. Here we construct the acoustic version of a type-II Weyl Hamiltonian by stacking one-dimensional dimerized chains of acoustic resonators. This acoustic type-II Weyl system exhibits distinct features in a finite density of states and unique transport properties of Fermi-arc-like surface states. In a certain momentum space direction, the velocity of these surface states is determined by the tilting direction of the type-II Weyl nodes rather than the chirality dictated by the Chern number. Our study also provides an approach of constructing acoustic topological phases at different dimensions with the same building blocks.
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Singapore 637371, Singapore.
authors.forename: Zhaoju
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Singapore 637371, Singapore.|Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637371, Singapore.
authors.forename: Baile
authors.initials: B
authors.lastname: Zhang