Efficient sorting of free electron orbital angular momentum. (27th February 2017)

• Record Type: Journal Article
• Authors: McMorran, Benjamin J; Harvey, Tyler R; Lavery, Martin P J
• Is Part Of: New journal of physics. Volume 19:Number 2(2017:Feb.)
• Publication Date: 2017-02-27
• Subjects: orbital angular momentum -- electron vortex -- electron microscopy; Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1367-2630/aa5f6f
• Languages: English
• ISSNs: 1367-2630

Abstract

Abstract: We propose a method for sorting electrons by orbital angular momentum (OAM). Several methods now exist to prepare electron wavefunctions in OAM states, but no technique has been developed for efficient, parallel measurement of pure and mixed electron OAM states. The proposed technique draws inspiration from the recent demonstration of the sorting of OAM through modal transformation. We show that the same transformation can be performed on electrons with electrostatic optical elements. Specifically, we show that a charged needle and an array of electrodes perform the transformation and phase correction necessary to sort OAM states. This device may enable the analysis of the spatial mode distribution of inelastically scattered electrons.