Micromagnets dramatically enhance effects of viscous hydrodynamic flow in two-dimensional electron fluid

TL;DR

This paper proposes using micromagnets to significantly increase vorticity in two-dimensional electron fluids, enhancing the visibility of viscous hydrodynamic effects and enabling more precise characterization and control of electron behavior.

Contribution

It introduces a novel method of employing micromagnets to dramatically boost vorticity in 2D electron fluids, improving measurement accuracy of hydrodynamic effects.

Findings

Micromagnets can increase vorticity by orders of magnitude.

Enhanced vorticity improves the detection of viscous effects.

The method enables better control and characterization of electron hydrodynamics.

Abstract

The hydrodynamic behavior of electron fluids in a certain range of temperatures and densities is well established in graphene and in 2D semiconductor heterostructures. The hydrodynamic regime is intrinsically based on electron-electron interactions, and therefore it provides a unique opportunity to study electron correlations. Unfortunately, in all existing measurements, the relative contribution of hydrodynamic effects to transport is rather small. Viscous hydrodynamic effects are masked by impurities, interaction with phonons, uncontrolled boundaries and ballistic effects. This essentially limits the accuracy of measurements of electron viscosity. Fundamentally, what causes viscous friction in the electron fluid is the property of the flow called vorticity. In this paper, we propose to use micromagnets to increase the vorticity by orders of magnitude. Experimental realization of this proposal will bring electron hydrodynamics to a qualitatively new precision level, as well as opening a new way to characterize and externally control the electron fluid.