Work

Paired Parton Trial States for the Superfluid-Fractional Chern Insulator Transition

Year: 2026

Type: article

Abstract: We consider a model of hard-core bosons on a lattice half-filling a Chern band such that the system has a continuous transition between a fractional Chern insulator (FCI) and a superfluid state (SF) depending on the bandwidth to bandspacing ratio. We construct a parton-inspired trial wave function Ansatz for the ground states that has remarkably high overlap with exact diagonalization in both phases and throughout the phase transition. Our Ansatz is stable to adding some bosonic interactions beyond the on-site hard-core constraint. We confirm that the transition is well described by a projective translation symmetry-protected multiple parton bandgap closure, as has been previously predicted. However, unlike prior work, we find that our wave functions require anomalous (BCS-like) parton correlations to describe the phase transition and SF phase accurately.

Source: Physical Review Letters

DOI: 10.1103/l9rp-y68y

Authors: Tevž Lotrič, Steven H. Simon

Institution: University of Oxford

Language: English

Topic: Topological Materials and Phenomena

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,750

Funders: Leverhulme Trust, Engineering and Physical Sciences Research Council