Free Majorana Fermion Meets Gauged Ising Conformal Field Theory on the Fuzzy Sphere (2509.08038v1)

Abstract: The fuzzy sphere regularisation is a powerful tool to study conformal field theories (CFT) in three spacetime dimensions. In this paper, we extend its scope to CFTs with local fermionic operators. We realise the free Majorana fermion CFT on a setup with one flavour of bosons and one flavour of fermions on the lowest Landau level with a $1/2$ angular momentum mismatch. We allow conversion between two bosons and two fermions, and use a relative chemical potential as the tuning parameter. On the phase diagram, we find three gapped phases, viz. a fermionic integer quantum Hall phase, an $f$-wave chiral topological superconductor, and a bosonic Pfaffian phase. They are separated by two continuous transitions described respectively by a free Majorana fermion and a gauged Ising CFT. We numerically confirm their emergent conformal symmetry through the operator spectrum. We also study the two-point correlation function of the Majorana fermion, and the topological Wilson line defect of the gauged Ising CFT. Our work represents a step towards studying interacting fermionic CFTs and regularising quantum field theories on the fuzzy sphere.