Defects on cylinders: superfluid helium films and bacterial cell walls

TL;DR

This paper explores the analogy between superfluid helium films on cylinders and bacterial cell wall dislocations, highlighting how confinement influences defect interactions and revealing differences due to the vector nature of dislocation charges.

Contribution

It reviews the physics of superfluid helium films on cylindrical surfaces and compares defect behaviors with dislocations in bacterial cell walls, emphasizing the effects of confinement and topological charge differences.

Findings

Confinement affects vortex interactions in superfluid helium films.

Dislocation behavior on cylinders differs due to vector topological charges.

Analogies between superfluid vortices and dislocation defects are clarified.

Abstract

There is a deep analogy between the physics of crystalline solids and the behavior of superfluids, dating back to pioneering work of Phillip Anderson, Paul Martin and others. The stiffness to shear deformations in a periodic crystal resembles the superfluid density that controls the behavior of supercurrents in neutral superfluids such as He^4. Dislocations in solids have a close analogy with quantized vortices in superfluids. Remarkable recent experiments on the way rod-shaped bacteria elongate their cell walls have focused attention on the dynamics and interactions of point-like dislocation defects in partially ordered cylindrical crystalline monolayers. In these lectures, we review the physics of superfluid helium films on cylinders and discuss how confinement in one direction affects vortex interactions with supercurrents. Although there are similarities with the way dislocations respond to strains on cylinders, important differences emerge, due to the vector nature of the topological charges characterizing the dislocations.