The Pfaffian state in an electron gas with small Landau level gaps
Abstract
Landau level mixing plays an important role in the Pfaffian (or anti-Pfaffian) states. In ZnO the Landau level gap is essentially an order of magnitude smaller than that in a GaAs quantum well. We introduce the screened Coulomb interaction in a single Landau level to tackle that situation. Here we study the overlap of the ground state and the Pfaffian (or anti-Pfaffian) state at evendenominator fractional quantum Hall (FQH) states present in ZnO. The overlap is strongly system size-dependent which suggests a newly proposed particle-hole symmetry Pfaffian ground state in the extreme Landau level mixing limit. When the ratio of Coulomb interaction to the Landau level gap \k{appa} varies, we find a possible topological phase transition in the range 2 < \k{appa} < 3, which was actually observed in an experiment. We then study how the width of quantum well combined with screening influences the overlap.
Keywords
Cite
@article{arxiv.1704.05107,
title = {The Pfaffian state in an electron gas with small Landau level gaps},
author = {Wenchen Luo and Tapash Chakraborty},
journal= {arXiv preprint arXiv:1704.05107},
year = {2018}
}
Comments
5 pages, 4 figures, accepted for publication as a rapid communication in PRB