Vorticity is a concept well established in fluid dynamics to describe the local tendency of a fluid to rotate. Here, we explore the vorticity of electron waves and show that it can be used to qualitatively estimate the strength of an electron magnetic circular dichroism (EMCD) signal, without resorting to expensive inelastic electron scattering calculations. We discuss the properties of vorticity, its relationship with orbital angular momentum, and how it can be used to investigate the characteristics of electron beams.

• Received 3 July 2016
• Revised 22 August 2016

DOI:https://doi.org/10.1103/PhysRevB.94.144430