Characterizing electronic scattering rates with transport in multiterminal devices

TL;DR

This paper demonstrates how multiterminal devices can be used to identify and quantify different electron transport regimes and scattering rates in two-dimensional systems without the need for space-resolved imaging.

Contribution

It introduces a method using a five-terminal geometry and a linearized Boltzmann model to distinguish transport regimes and extract scattering rates from current partition data.

Findings

Current partition diagnoses transport regime crossover.

Scattering rates can be extracted without space-resolved imaging.

Signatures of the tomographic regime are identifiable.

Abstract

Strongly interacting electrons in clean two-dimensional devices are theorized to exhibit many distinct transport regimes, such as ballistic, hydrodynamic, or diffusive. Realistic samples often lie in crossover regimes between these idealized limits. We show how a single experiment on a multiterminal device can distinguish these regimes and constrain the relevant scattering rates without space-resolved imaging. Using a linearized Boltzmann model in a five-terminal geometry, we find that current partition among the drain contacts diagnoses the ballistic-hydrodynamic-Ohmic crossover and allows extraction of momentum-relaxing and momentum-conserving scattering rates in the crossover regime. The same geometry also exhibits clear signatures of the tomographic regime, potentially allowing for a quantitative discrimination between viscous and tomographic flow in experiments. Our results demonstrate that multiterminal devices are a simpler experimental route to characterize transport regimes in electron liquids, relative to space-resolved imaging experiments.