Amorphous Chiral Fermions as Editors' Suggestion in Physical Review Materials

Our framework for stabilizing amorphous chiral topological semimetals using symmetry group theory and structural chirality was published this past week as an Editors’ Suggestion in Physical Review Materials.

Topologically chiral semimetals (chiral TSMs), including Weyl and multifold fermion semimetals, have been a major area of research interest since their prediction 15 years ago, owing to their potential promise in industry-relevant applications such as enantioselective photoresponse and topologically enhanced chemical catalysis. In our earlier work, we identified real-space structural chirality as a knob for generating ideal chiral TSM phases, leading to their discovery in RhSi and related chiral materials. However, earlier theoretical studies predicted that moderate structural disorder destroys chiral TSMs, limiting reliable material predictions to highly crystalline samples. Nevertheless, recent experiments have identified signatures of chiral TSM states in highly disordered and even amorphous materials. To resolve this contradiction, we employed extensive numerical calculations guided by average symmetry group theory. Through this, we discovered that topological signatures of chiral TSM states can survive down the amorphous regime in the presence of local chirality order, in which the local chemical bonding environment carries the same handedness over long distances in otherwise strongly disordered systems. Our findings pave the way towards identifying topology and wavefunction geometry in first-principles simulations of real amorphous materials, facilitating a direct connection to experiments on noncrystalline samples. Further details are available through the English and French news coverage by the IPhT.

Oct. 14, 2026