Electronic Poiseuille Flow in Hexagonal Boron Nitride Encapsulated Graphene FETs

TL;DR

This study demonstrates viscous electron flow in high-mobility graphene FETs, showing that hydrodynamic effects persist from 178 K to room temperature, enabling potential electronic hydrodynamic devices.

Contribution

It provides experimental evidence of viscous electron flow in graphene at near-room temperatures and offers design insights for hydrodynamic electronic devices.

Findings

Viscous effects observed from 178 K to room temperature.

Finite element models support experimental results.

Design guidelines for devices with enhanced viscous effects.

Abstract

Electron-electron interactions in graphene are sufficiently strong to induce a correlated and momentum-conserving flow such that charge carriers behave similarly to the Hagen-Poiseuille flow of a classical fluid. In the current work, we investigate the electronic signatures of such a viscous charge flow in high-mobility graphene FETs. In two complementary measurement schemes, we monitor differential resistance of graphene for different channel widths and for different effective electron temperatures. By combining both approaches, the presence of viscous effects is verified in a temperature range starting from 178 K and extending up to room temperature. Our experimental findings are supported by finite element calculations of the graphene channel, which also provide design guidelines for device geometries that exhibit increased viscous effects. The presence of viscous effects near room temperature opens up avenues for functional hydrodynamic devices such as geometric rectifiers like a Tesla valve and charge amplifiers based on electronic Venturi effect.