Coulomb drag at \nu = 1/2: Composite fermion pairing fluctuations

TL;DR

This paper investigates Coulomb drag at filling factor 1/2 in double-layer 2D electron systems, highlighting how pairing fluctuations of composite fermions influence transresistivity and are sensitive to experimental parameters.

Contribution

It introduces a strong coupling approach to analyze pairing fluctuations of composite fermions and their effect on Coulomb drag near the critical temperature.

Findings

Pairing fluctuations increase transresistivity as temperature decreases.

The pairing mechanism is highly sensitive to density differences and current.

Potential connection to experimental observations by Lilly et al.

Abstract

We consider the Coulomb drag between two two-dimensional electron layers at filling factor \nu = 1/2 each, using a strong coupling approach within the composite fermion picture. Due to an attractive interlayer interaction, composite fermions are expected to form a paired state below a critical temperature T_c. We find that above T_c pairing fluctuations make the longitudinal transresistivity \rho_D increase with decreasing temperature. The pairing mechanism we study is very sensitive to density variations in the two layers, and to an applied current. We discuss possible relation to an experiment by Lilly et al. [Phys. Rev. Lett. 80, 1714 (1998)].