Very high-energy collective states of partons in fractional quantum Hall liquids

TL;DR

This paper reveals high-energy collective states in fractional quantum Hall liquids that are best described by parton quasiparticles, supported by numerical, wave function, and field theory analyses, expanding understanding of topological phases.

Contribution

It introduces a new high-energy collective mode in Jain states, interpreted as a parton GMP mode, supported by microscopic wave functions and effective field theory derivations.

Findings

Identification of a high-energy collective mode as a parton GMP mode

Agreement between variational energies and exact diagonalization results

Derivation of a field theory for Jain states incorporating partons

Abstract

The low energy physics of fractional quantum Hall (FQH) states -- a paradigm of strongly correlated topological phases of matter -- to a large extent is captured by weakly interacting quasiparticles known as composite fermions (CFs). In this paper, based on numerical simulations and effective field theory, we argue that some \emph{high energy} states in the FQH spectra necessitate a different description based on \emph{parton} quasiparticles. We show that Jain states at filling factor $\nu{=}n/(2pn\pm1)$ with integers $n,p{\geq}2$, support two kinds of collective modes: in addition to the well-known Girvin-MacDonald-Platzman (GMP) mode, they host a high energy collective mode, which is interpreted as the GMP mode of partons. We elucidate observable signatures of the parton mode in the dynamics following a geometric quench. We construct a microscopic wave function for the parton mode, and demonstrate agreement between its variational energy and exact diagonalization. Using the parton construction, we derive a field theory of the Jain states and show that the previously proposed effective theories follow from our approach. Our results point to partons being "real" quasiparticles which, in a way reminiscent of quarks, only become observable at sufficiently high energies.