Micromagnetic manipulation of resistance in a 2-dimensional viscous electron flow

Electron transport in most solid state systems is dominated by extrinsic factors, such as sample geometry and scattering from impurities, and is essentially independent of the intrinsic properties of the electron system. An exception is the hydrodynamic regime, where Coulomb interactions transform the electron motion from independent particles to the collective motion of a viscous ‘electron fluid’. The fluid viscosity is an intrinsic property of the electron system, determined solely by the electron-electron interactions. However, the viscous behaviour only affects the sample resistance when there is a nonuniformity in flow, induced due to boundary roughness or density variation. We show that viscous transport can be enabled and manipulated by a spatially varying magnetic field. We analyze the electron flow in an 2D electron system that lies below an array of micromagnets with a saturation field of ~1T. We optimize the placement and geometry of micromagnets to maximize the effect on viscous flow and discuss the implications for future experiments.

About the presenter

Dr Aydin C. Keser is a theoretical postdoctoral researcher working with Dr Dimitrie Culcer at UNSW on transport properties of surface states in topological materials, including disorder and interaction effects. Dr Keser completed his master’s and PhD in the University of Maryland as a Fulbright visiting scholar and he is a member of the American Physical Society. He is currently working on non-universal corrections to transport due to interactions between carriers, as part of FLEET’s Research Theme 1, topological materials.