2026/07/16 by Zhaoyu Han, Ashvin Vishwanath, Eslam Khalaf
Physics and Astronomy · #cond-mat.str-el
We propose an unconventional metallic phase emerging on doping the 1/3 Fractional Chern insulator, which can serve as a parent state to anyon superconductivity with arbitrary chiral central charge. It is a twisted ℤ3 orthogonal metal: a state with vanishing electron quasiparticle weight but a single well-defined Fermi surface of emergent charge-e/3 fermions coupled to a Dijkgraaf-Witten twisted ℤ3 gauge field. It is manifestly valley-symmetric and valley-gapped. Pairing this fractionalized Fermi surface then removes the topological order and produces a family of superconductors whose chiral central charge is directly set by the BdG band topology of the paired e/3 fermions, while the angular momentum of the physical order parameter is constrained to be a multiple of three. This scenario provides a route to superconducting states beyond anyon-superconductivity constructions based on 2e/3 anyons. The metallic phase itself carries distinctive ``fractional Fermiology'' signatures: e/3 shot noise, anomalous quantum oscillations, and a 6π ac Josephson effect when it mediates the Josephson coupling between superconductors. We construct explicit wavefunction ansatz realizing the phase, and argue that inter-valley repulsion between anyons stabilizes this phase compared to competing states. We show that the construction extends to higher Laughlin states but not to Jain states.