An algebraic approach to FQHE variational wave functions

TL;DR

This paper introduces a new algebraic method to construct variational wave functions for fractional quantum Hall systems at certain filling factors, extending Laughlin's work and linking graph theory with quantum many-body states.

Contribution

It develops a systematic algebraic approach using graph invariants to construct variational wave functions for FQHE states at specific filling factors, generalizing previous results.

Findings

Constructed d-regular multi-graphs with nonzero symmetrization

Extended Laughlin's correlation to broader filling factors

Linked graph invariants to quantum wave function construction

Abstract

Consider a system of $N$ electrons projected onto the lowest Landau level (LLL) with filling factor of the form $n/(2pn\pm1)<1/2$ and $N$ a multiple of $n$. We show that there always exists a two-dimensional symmetric correlation factor (arising as a nonzero symmetrization) for such systems and hence one can always write a variational wave function. This extends an earlier observation of Laughlin for an incompressible quantum liquid (IQL) state with filling factor equal to the reciprocal of an odd integer $ \geq 3$. To do so, we construct a family of $d$-regular multi-graphs on $N$ vertices for any $N$ whose graph-monomials have nonzero linear symmetrization and obtain, as special cases, the aforementioned nonzero correlations for the IQL state. The nonzero linear symmetrization that is obtained is in fact an example of what is called a binary invariant of type $(N,d)$. Thus, in addition to supplying new variational wave functions for systems of interacting Fermions, our construction is of potential interest from both the graph and invariant theoretic viewpoints.