Orbital angular momentum resolved electron magnetic chiral dichroism

Abstract

We propose a highly efficient atomically-resolved mode of electron magnetic chiral dichroism. This method exploits the recently introduced orbital angular momentum spectrometer to analyze the inelastically scattered electrons allowing for simultaneous dispersion in both energy and angular momentum. The technique offers several advantages over previous formulations of electron magnetic chiral dichroism as it requires much simpler experimental conditions in terms of specimen orientation and thickness. A novel simulation algorithm, based on the multislice description of the beam propagation, is used to anticipate the advantages of the new approach over current electron magnetic chiral dichroism implementations. Numerical calculations confirm an increased magnetic signal to noise ratio with in plane atomic resolution.

Entanglement of Orbital Angular Momentum in Non-Sequential Double Ionization

“…The measurement of OAM for electron vortex beams, has received a great deal of attention and a variety of methods have been demonstrated [67,[78][79][80][81][82]. Most promising is the so-called OAM sorter [81,82], this has been proposed [83,84] and experimentally demonstrated [85] as an OAM analyzing element to an electron microscope. Thus, such an element could be conceivably added to a typical reaction microscope (ReMi) [86][87][88] employed for NSDI-a ReMi measures correlation of the ion and the two electrons, thus, it is already well-suited for studying entanglement [89].…”

Alignment of electron optical beam shaping elements using a convolutional neural network

“…The main effect of this aberration is broadening of the beam in the radial direction (P r ), which depends on the sign of the defocus. The OAM resolution is preserved instead, meaning that a moderate amount of defocus f can be tolerated if only the OAM component is of interest [42,43,44,45,46]. A more prominent source of resolution loss is the size mismatch (SM) between the beam and element S2 (Fig.…”

Combination of Electron Energy-loss Spectroscopy and Orbital Angular Momentum Spectroscopy. Applications to Electron Magnetic Chiral Dichroism, Plasmon-loss, and Core-loss

“…According to our simulations, it should be possible to produce atomic-resolution EMCD maps. [3] This result would be of immense practical interest. The channeling should permit analysis of the results in terms of electronic properties to be simplified.…”

“…CNR -Istituto Nanoscienze, Modena, Emilia-Romagna, Italy, 2 Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Jülich, Nordrhein-Westfalen, Germany, 3 Università di Modena e Reggio Emilia, Modena, Emilia-Romagna, Italy, 4 University of Ottawa, Ottawa, Ontario, Canada, 5 Forschungszentrum Juelich, Juelich, Nordrhein-Westfalen, Germany Electron energy-loss spectroscopy (EELS) is a powerful technique for measuring the energy state of electrons after scattering. It has had incredible success in measuring the atomic and chemical properties of materials, allowing chemical maps to be recorded with atomic spatial resolution.…”