Emergent dynamics of scale-free interactions in fractional quantum Hall fluids

TL;DR

This paper explores how scale-free interactions influence the emergent properties of fractional quantum Hall fluids, providing exact model Hamiltonians and proposing experimental realizations for robust non-Abelian phases.

Contribution

It introduces a new class of model Hamiltonians with scale-free interactions applicable to multiple Landau levels, advancing understanding of topological phases in quantum Hall systems.

Findings

Scale-free interactions can dominate Landau level mixing at high filling factors.

Exact null spaces of these Hamiltonians are analytically obtainable and generalize conformal Hilbert spaces.

A proposed experimental platform could realize these Hamiltonians, leading to robust non-Abelian quantum Hall phases.

Abstract

We show that even in the limit of large cyclotron gap, Landau level (LL) mixing can be dominant with scale-free interaction between charged ``elementary particles" in a fractional quantum Hall system, as long as the filling factor exceeds certain critical values. The corresponding Hamiltonians with scale-free interaction can serve as exact model Hamiltonians for certain composite Fermion or parton states (unlike the well-known TK Hamiltonians where the number of LLs needs to be fixed by hand), and they are natural physical Hamiltonians for 2D systems embedded in higher-dimensional space-time. Even with LL mixing the null spaces of such Hamiltonians (spanned by the ground state and the quasiholes) can be analytically obtained, and we show these are the generalisation of the conformal Hilbert spaces (CHS) to more than one LLs. The effective interaction between the anyons for these topological phases emerges from the kinetic energy of the ``elementary particles", leading to an interesting duality between strongly and weakly interacting systems that can be easily understood via the tuning of parameters in the scale-free interaction. We also propose a novel experimental platform for approximately realising such model Hamiltonians with trion like particles, that can potentially lead to very robust (non-Abelian) FQH phases from two-body Coulomb-based interaction.