HyperDet Wavefunction: A Phase-Agnostic Ansatz for Strongly Correlated Systems
Describing competing phases of strongly correlated systems often requires trial wave functions built from phase-specific assumptions. We propose the \emph{hyperdeterminant (HyperDet) wavefunction} as a phase-agnostic ansatz for both bosonic and fermionic quantum many-body systems exhibiting spontaneous symmetry-breaking order, fractionalization, and/or topological order with anyonic excitations. The HyperDet structure emerges naturally by fusing auxiliary fermionic parton Slater determinants into physical orbitals through a fully learnable \emph{fusion tensor} $\mathcal F$. Optimized using variational Monte Carlo, a single HyperDet architecture can achieve exceptionally high overlaps $\geq 99.9\%$ with exact-diagonalization ground states throughout the entire fractional Chern insulator phase in both bosonic and fermionic models, and across their nearby competing phases. We introduce the singular-value spectrum of the \emph{bipartite fusion matrix} as a structural diagnostic of fusion tensor, and find that its redistribution tracks many-body phase transitions without computing phase-specific observables. The optimized fusion tensor also encodes the parton-level topological data: it reproduces the parton Chern numbers expected for the bosonic and fermionic FCI states, completing their field-theory descriptions and the resulting topological order. Its intrinsic gauge structure further determines whether physical symmetries admit virtual lifts and, when faithful lifts exist, extracts their projective class; for the bosonic FCI, this recovers the expected parton translation fractionalization. We thus anticipate the HyperDet wavefunction to be a promising variational platform for both accurate ground-state searches and phase-diagram explorations across strongly correlated phases, and for providing interpretable theoretical insights from parton-level microscopics to field-theory descriptions.