Chiral quantum chaos around exponentially many zero modes in the quantum breakdown model
The paper classifies symmetries and spectral statistics for a quantum breakdown model of interacting fermions. It shows that these interactions realize all five Altland-Zirnbauer classes with chiral symmetry, leading to universal Wigner-Dyson bulk statistics. Crucially, the system protects an exponentially large number of zero energy modes dictated by a growing chiral index.