We propose the design of a space-variantWien filter for electron beams that induces a spin half-turn and converts the corresponding spin angular momentum variation into orbital angular momentum of the beam itself by exploiting a geometrical phase arising in the spin manipulation. When applied to a spatially coherent input spin-polarized electron beam, such a device can generate an electron vortex beam, carrying orbital angular momentum. When applied to an unpolarized input beam, the proposed device, in combination with a suitable diffraction element, can act as a very effective spin-polarization filter. The same approach can also be applied to neutron or atom beams.
Spin-to-Orbital Angular Momentum Conversion and Spin Polarization Filtering in Electron Beams / Karimi, Ebrahim; Marrucci, Lorenzo; V., Grillo; Santamato, Enrico. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 108:(2012), pp. 044801-044803. [10.1103/PhysRevLett.108.044801]
Spin-to-Orbital Angular Momentum Conversion and Spin Polarization Filtering in Electron Beams
KARIMI, ebrahim;MARRUCCI, LORENZO;SANTAMATO, ENRICO
2012
Abstract
We propose the design of a space-variantWien filter for electron beams that induces a spin half-turn and converts the corresponding spin angular momentum variation into orbital angular momentum of the beam itself by exploiting a geometrical phase arising in the spin manipulation. When applied to a spatially coherent input spin-polarized electron beam, such a device can generate an electron vortex beam, carrying orbital angular momentum. When applied to an unpolarized input beam, the proposed device, in combination with a suitable diffraction element, can act as a very effective spin-polarization filter. The same approach can also be applied to neutron or atom beams.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.