Coulomb drag at zero temperature

TL;DR

This paper demonstrates that Coulomb drag saturates at low temperatures and is strongest in low mobility samples, challenging previous assumptions about its temperature dependence and relation to strongly-coupled states.

Contribution

It reveals that Coulomb drag at zero temperature scales inversely with the cube of conductance, showing saturation and mobility dependence at third order in interactions.

Findings

Coulomb drag saturates at low temperatures.

Zero-temperature transresistance scales as inverse cube of conductance.

Drag is strongest in low mobility samples.

Abstract

We show that the Coulomb drag effect exhibits saturation at small temperatures, when calculated to the third order in the interlayer interactions. The zero-temperature transresistance is inversely proportional to the third power of the dimensionless sheet conductance. The effect is therefore the strongest in low mobility samples. This behavior should be contrasted with the conventional (second order) prediction that the transresistance scales as a certain power of temperature and is almost mobility-independent. The result demonstrates that the zero-temperature drag is not an unambiguous signature of a strongly-coupled state in double-layer systems.