Parent Hamiltonians for lattice Halperin states from free-boson conformal field theories

TL;DR

This paper constructs parent Hamiltonians for lattice Halperin states derived from free-boson conformal field theories, revealing their relation to chiral $t$-$J$-$V$ models and identifying their low-energy conformal field theory descriptions.

Contribution

It introduces a family of lattice states from deformations of Wess-Zumino-Witten models and derives their long-range parent Hamiltonians, connecting them to known fractional quantum Hall states and conformal field theories.

Findings

Derived long-range SU(2) invariant parent Hamiltonians for lattice Halperin states.

Connected the low-energy spectrum to a two-component free boson conformal field theory.

Extended inverse-square $t$-$J$-$V$ models to open chains with similar low-energy descriptions.

Abstract

We introduce a family of many-body quantum states that describe interacting spin one-half hard-core particles with bosonic or fermionic statistics on arbitrary one- and two-dimensional lattices. The wave functions at lattice filling fraction $\nu=2/(2m+1)$ are derived from deformations of the Wess-Zumino-Witten model $\mathfrak{su}(3)_1$ and are related to the $(m+1,m+1,m)$ Halperin fractional quantum Hall states. We derive long-range SU(2) invariant parent Hamiltonians for these states which in two dimensions are chiral $t$-$J$-$V$ models with additional three-body interaction terms. In one dimension we obtain a generalisation to open chains of a periodic inverse-square $t$-$J$-$V$ model proposed in [Z. N. C. Ha and F. D. M. Haldane, Phys. Rev. B $\mathbf{46}$, 9359 (1992)]. We observe that the gapless low-energy spectrum of this model and its open-boundary generalisation can be described by rapidity sets with the same generalised Pauli exclusion principle. A two-component compactified free boson conformal field theory is identified that has the same central charge and scaling dimensions as the periodic bosonic inverse-square $t$-$J$-$V$ model.