spin polarized electron

An electron exhibits "up" state or "down" state corresponding to the quantum numbers ±1/2. Recently, a new electron gun technology using a photocathode made of a strained super lattice semiconductor enables the emission of electrons with a spin polarization of more than 90 % at room temperature. Originally, the electron source was developed for collision experiments in the field of elementary particle physics. However, due to the increase of its brightness, the source has recently been applied to photoelectron surface microscopes and transmission electron microscopes (TEM). Then, surface images and TEM images have been obtained. A TEM equipped with the gun allows us to observe the interaction between the incident electron spin and the spins and magnetic moments of the atoms in a specimen.