Few-body treatment of the quantum Hall system

Nathan Gemelke

Bo Yang

We show that there is an emergent lattice description for the continuous fractional quantum Hall (FQH) systems, with a generalized set of few-body coherent states. In particular, model Hamiltonians of the FQH effect (FQHE) are equivalent to the real-space von Neumann lattice of local projection operators imposed on a continuous system in the thermodynamic limit. It can be analytically derived that tuning local one-body potentials in such lattices amounts to the tuning of individual two- or few-body pseudopotentials. For some cases, we can realize pure few-body pseudopotentials important for stabilizing exotic non-Abelian topological phases. Thus, this new approach can potentially lead to the experimental realization of coveted non-Abelian quantum fluids including the Moore-Read state and the Fibonacci state. The reformulation of the FQHE as a sum of local projections opens up new paths for rigorously proving the incompressibility of microscopic Hamiltonians in the thermodynamic limit.

Kun Yang

建一 浅野

Rachel Wooten, Bin Yan, Chris H. Greene

A relative coordinate breathing mode in the quantum Hall system is predicted to exist with different behavior under either Coulomb or dipole-dipole interactions. While Kohn's theorem [W. Kohn, Phys. Rev. 123, 1242 (1961)] predicts that any relative coordinate interaction will fail to alter the center-of-mass energy spectrum, it can affect excitations in the relative coordinates. One such collective excitation, which we call the hyperradial breathing mode, emerges naturally from a few-body, hyperspherical representation of the problem and depends on the interparticle interactions, the ground state wave function, and the number of particles participating in the excitation. Possible observations of this excitation will be discussed in the context of both conventional quantum Hall experiments and cold, rotating atomic simulations.

Bartosz Kuśmierz, Arkadiusz Wójs

The family of ``Jack states'' related to antisymmetric Jack polynomials are the exact zero-energy ground states of particular model short-range many-body repulsive interactions, defined by a few nonvanishing leading pseudopotentials. Some Jack states are known or anticipated to accurately describe many-electron incompressible ground states emergent from the two-body Coulomb repulsion in the fractional quantum Hall effect. By extensive numerical diagonalization, we demonstrate the emergence of Jack states from suitable pair interactions. We find empirically a simple formula for the optimal two-body pseudopotentials for the series of most prominent Jack states generated by contact many-body repulsion. Furthermore, we seek a realization of arbitrary Jack states in realistic quantum Hall systems with Coulomb interaction, i.e., in the partially filled lowest and excited Landau levels in quasi-two-dimensional layers of conventional semiconductors such as GaAs or in graphene.