Perfect spin-fillter and spin-valve in carbon atomic chains

TL;DR

This paper demonstrates that carbon atomic chains connected to graphene electrodes can act as nearly perfect spin-filters and giant spin-valves, offering promising applications in all-carbon spintronics.

Contribution

It introduces the first ab initio demonstration of simultaneous spin-filter and spin-valve effects in carbon atomic chains with graphene electrodes.

Findings

Achieve nearly 100% spin polarization as spin-filters.

Demonstrate bias-dependent magnetoresistance up to 1,000,000%.

Properties are independent of chain length.

Abstract

We report ab initio calculations of spin-dependent transport in single atomic carbon chains bridging two zigzag graphene nanoribbon electrodes. Our calculations show that carbon atomic chains coupled to graphene electrodes are perfect spin-filters with almost 100 % spin polarization. Moreover, carbon atomic chains can also show a very large bias-dependent magnetoresistance up to 1000000 % as perfect spin-valves. These two spin-related properties are independent on the length of carbon chains. Our report, the spin-filter and spin-valve are conserved in a single device simultaneously, opens a new way to the application of all-carbon composite spintronics.