ACTIVITIES

V.Grillo is coordinating the QSORT  project that is  now  finishing but leading a long term legacy on the beam shaping and electron microscopy in general. Among these the MINEON project and SMART electrons.

Some of his group activities are here presented

MEASURING ORBITAL ANGULAR MOMENTUM
( toward single electron experiments?)

Inspired by a similar optical device we are working on a sorter of Orbital Angular Momentum (OAM). This device transform an electron OAM in a linear momentum through a coordinate transformation operated through 2 holograms or  two MEMS based phase elements

More details are available
https://arxiv.org/abs/1609.09129

https://arxiv.org/abs/1910.03706

We have also proposed a device based on conductive cylinder that could measure the azimuthal current in a conductor.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.117.154801

MEMS based electron optics

I also think that miniaturized electron optics are here to stay and we  are finding new solutions for creating more device shapes and increasing the number of contacts to make this electron optics  more flexible than standard one. We can add new functionalities and open to new observables thanks to this idea.

We are also considering  going to a commercial product and we are studying this possibility in the context of MINEON.

The winning technology will be the joint use of artificial intelligence and MEMS  to make  extreme experiments finally possible.

HOLOGRAPHIC BEAM SHAPING

We created the first phase hologram to change the phase of an electron wavefunction.

In particular thanks to the use of a triangular shaped groove we could generate vortex beams at high efficiency.
We also generated Bessel beam by holographic methods

We also created the first giant vortex beam with Orbital Angular Momentum L=200h

Here you can see the experiment , the simulation , the map of the singularity and the spectrum of the actual L distribution.

SPIN-ORBITAL ANGULAR MOMENTUM THEORY AND EXPERIMENTS

We created the first multislice simulation based on Pauli equation and described the spin-orbit interaction in a magnetic lens

QUANTITATIVE STEM

The group and in particular V.Grillo has a long experience in quantitative STEM . Grilo has created the first quantitative anlysis of composition based on STEM.

Current interest are in the direction of finding the 3D position of dopant atoms inside a matrix using variable channeling conditions.

TEM METHODOLOGY:
Geometric phase analysis of strain
Convegent Beam analyis
Transport of Intensity equation

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