Spin polarization of electrons field-emitted from Cr thin film deposited on W<001> tips

In this study, we measured spin polarization of electrons field-emitted from a topological antiferromagnetic Cr(001) surface, which is expected to generate a high and stable spin-polarized electron beam. When the Cr thin film deposited on a W<;001> tip was thicker than 20 nm, the spin polarization of the field-emitted electrons reached 50%. Furthermore, the magnitude and direction of the spin polarization were stable for 90 min. These results indicate that topological antiferromagnetic material is more effective than common ferromagnets as the cathode material of spin-polarized field emitters to achieve high and stable spin polarization.