Shearing the Vacuum - Quantum Friction

TL;DR

This paper investigates quantum friction between two smooth, featureless surfaces at zero temperature, revealing significant frictional effects driven by electromagnetic reflection properties and material resistivities.

Contribution

It demonstrates that quantum friction can be substantial for materials with specific resistivities and close separation, depending on electromagnetic reflection characteristics.

Findings

Frictional forces comparable to everyday friction can occur at nanoscales.

Friction depends on electromagnetic reflection coefficients and material resistivity.

Behavior varies with shear velocity and surface separation.

Abstract

We consider two perfectly smooth featureless surfaces at T=0, defined only by their respective dielectric functions, separated by a finite distance, and ask the question whether they can experience any friction when sheared parallel to their interface. We find large frictional effects comparable to everyday frictional forces provided that the materials have resistivities of the order of 1 m-Ohm and that the surfaces are in close proximity. The friction depends solely on the reflection coefficients of the surfaces to electromagnetic waves and its detailed behaviour with shear velocity and separation is dictated by the dispersion of the reflectivity with frequency.