Singular Pair Breaking in the Composite Fermi Liquid Description of the Half-Filled Landau Level

TL;DR

This paper investigates how gauge field fluctuations influence pairing transitions in the composite Fermi liquid at half-filled Landau levels, revealing conditions for first-order or continuous transitions based on interaction types.

Contribution

It demonstrates that gauge fluctuations cause pair breaking in all channels and identifies the conditions under which pairing transitions are first order or continuous.

Findings

Gauge fluctuations induce pair breaking in all angular momentum channels.

Short-range interactions lead to first-order pairing transitions.

Coulomb interactions allow for continuous pairing transitions.

Abstract

Fluctuations of the Chern-Simons gauge field in the composite Fermi liquid description of the half-filled Landau level are pair breaking in all angular momentum channels. For short-range electron-electron interactions these fluctuations are sufficiently strong to drive any T=0 pairing transition first order. For Coulomb interactions these fluctuations are weaker and a continuous transition is possible.