An all-metallic logic gate based on a ferromagnetic metal nanocontact

The domain wall in ferromagnetic materials can be driven by an electric current, and the information written and read out through the current. However, how to realize such functions in realistic devices is not clear yet. Using electron beam lithography and the lift-off technique we have successfully fabricated ferromagnetic metal nanocontacts and all-metallic logical gates, and have studied the spin-dependent electron transport properties of the nanocontacts as well as the performance of the gates. The domain wall can be pinned at the contact position and pushed away by the reflection of spin-polarized electrons, with the direction of the domain wall motion determined by the specific structural design. Based on our analysis of the properties of the nanocontact domain wall we have designed and fabricated an all-metallic logic gate, which can perform a logical NOT operation very well.