The Composite Particle-Hole Spinor of the Lowest Landau Level

TL;DR

This paper introduces a two-component effective field theory for the lowest Landau level, combining composite electrons and holes into a particle-hole spinor that exhibits emergent pseudospin and parallels Dirac composite fermion theory.

Contribution

It develops a novel two-component particle-hole spinor framework that unifies composite electrons and holes with emergent pseudospin, matching the Dirac composite fermion theory in the non-relativistic limit.

Findings

The theory cancels Chern-Simons terms for electrons and holes.

A pseudospin degree of freedom emerges naturally.

The model aligns with the non-relativistic limit of Dirac composite fermions.

Abstract

We propose to form a two-component effective field theory from L = (L_ce + L_ch)/2, where L_ce is the Lagrangian of composite electrons with a Chern-Simons term, and L_ch is the particle-hole conjugate of L_ce - the Lagrangian of composite holes. In the theory, the two-component fermion field phi is a composite particle-hole spinor coupled to an emergent effective gauge field in the presence of a background electromagnetic field. The Chern-Simons terms for both the composite electrons and composite holes are exactly cancelled out, and a 1/2 pseudospin degree of freedom, which responses to the emergent gauge field the same way as the real spin to the electromagnetic field, emerges automatically. Furthermore, the composite particle-hole spinor theory has exactly the same form as the non-relativistic limit of the massless Dirac composite fermion theory after expanded to the four-component form and with a mass term added.