Comparative study of screened inter-layer interactions in the Coulomb drag effect in bilayer electron systems

TL;DR

This paper systematically compares models of inter-layer interactions in bilayer electron systems to understand Coulomb drag effects, emphasizing the importance of including correlation effects for accurate theoretical predictions matching recent low-density experiments.

Contribution

It introduces a comprehensive comparison of various static local-field correction models for inter-layer interactions, highlighting their impact on Coulomb drag calculations in low-density regimes.

Findings

Correlation effects are crucial for accurate drag resistivity predictions.

Static local-field corrections improve agreement with experimental data.

Effective inter-layer interactions with static correlations describe recent low-density experiments well.

Abstract

Coulomb drag experiments in which the inter-layer resistivity is measured are important as they provide information on the Coulomb interactions in bilayer systems. When the layer densities are low correlation effects become significant to account for the quantitative description of experimental results. We investigate systematically various models of effective inter-layer interactions in a bilayer system and compare our results with recent experiments. In the low density regime, the correlation effects are included via the intra- and inter-layer local-field corrections. We employ several theoretical approaches to construct static local-field corrections. Our comparative study demonstrates the importance of including the correlation effects accurately in the calculation of drag resistivity. Recent experiments performed at low layer densities are adequately described by effective inter-layer interactions incorporating static correlations.