Landau level mixing and the emergence of Pfaffian excitations for the 5/2 fractional quantum Hall effect

TL;DR

This study uses exact diagonalization to explore how Landau level mixing influences the 5/2 fractional quantum Hall effect, revealing conditions where the Pfaffian model accurately describes the system's ground and excited states, supporting nonabelian statistics.

Contribution

It demonstrates that Landau level mixing can be incorporated via an effective interaction, identifying an experimentally accessible phase where the Pfaffian state is valid for both ground and excitations.

Findings

Pfaffian model accurately describes the ground state and excitations in certain conditions

Landau level mixing can be effectively incorporated into the model

Results support the persistence of the 5/2 Hall effect at low magnetic fields

Abstract

We report on exact diagonalization studies for fully spin polarized 5/2 fractional quantum Hall effect, incorporating Landau level mixing through the Bishara-Nayak effective interaction. We find that there is an experimentally accessible region in the phase diagram where the Pfaffian model accurately describes not only the ground state but also the neutral and charged excitations. These results are consistent with the observed persistence of the 5/2 Hall effect down to very low magnetic fields; they are also relevant to the experimental attempts to detect nonabelian braid statistics.