Approximate two-body generating Hamiltonian for the PH-Pfaffian wavefunction

TL;DR

This paper introduces two approximate two-body Hamiltonians that generate the PH-Pfaffian wavefunction with high fidelity, reproducing key physical properties and favoring the PH-Pfaffian phase energetically.

Contribution

The authors develop and validate two specific two-body Hamiltonians that closely approximate the PH-Pfaffian wavefunction across various system sizes, advancing understanding of its physical realization.

Findings

High overlap with the original wavefunction

Reproduces low-lying entanglement spectrum and structure factor

PH-Pfaffian shift is energetically favorable

Abstract

We present two 2-body Hamiltonians that approximate the exact PH-Pfaffian wavefunction with their ground states for all the system sizes where this wavefunction has been numerically constructed to date. The approximate wavefunctions have high overlap with the original and reproduce well the low-lying entanglement spectrum and structure factor. The approximate generating Hamiltonians are obtained by an optimisation procedure where three to four pseudopotentials are varied in the neighbourhood of second Landau level Coulomb interaction or of a non-interacting model. They belong to a finite region in the variational space of Hamiltonians where each point approximately generates the PH-Pfaffian. We diagonalize the identified Hamiltonians for up to 20 electrons and find that for them the PH-Pfaffian shift appears energetically more favorable. Possibility to interpret the data in terms of composite fermions is discussed.