Voltage-controlled spin injection with an endohedral fullerene CoC$_{60}$ dimer

TL;DR

This paper theoretically demonstrates that a Co@C60 fullerene dimer with gold electrodes can achieve high spin polarization and efficient spin injection, enabling ultra-small, gate-controlled spintronic devices without ferromagnetic components.

Contribution

It introduces a novel voltage-controlled spin injection device using an endohedral fullerene dimer, showing high spin polarization without ferromagnetic electrodes.

Findings

Density of states spin polarization up to 95%.

Current exhibits strong spin polarization up to 100%.

Device enables electrostatic tuning of spin injection.

Abstract

Spin-dependent transport through an endohedral fullerene Co@C$_{60}$ dimer with gold electrodes is explored theoretically using density functional and extended H\"{u}ckel theory. Density of states spin polarizations up to 95%, due to spin-splitting of Co 3d orbitals, are found by varying the gate and/or bias voltage. The current-voltage characteristics and strong (up to 100%) spin polarization of the current indicate that the device can be utilized for highly efficient spin injection into nonmagnetic conductors. This finding opens the way to the realization of electrostatically tuned spintronic nano devices less than 2 nanometers in size, without ferromagnetic electrodes.