Proposal for a dual spin filter based on [VO(C$_3$S$_4$O)$_2$]$^{2-}$

TL;DR

This paper demonstrates through DFT calculations that the [VO(C$_3$S$_4$O)$_2$]$^{2-}$ molecule can act as a dual spin filter, switching between spin-up and spin-down conduction states with an external electrostatic gate, promising for spintronics.

Contribution

The study introduces a new vanadium-based molecular spin filter capable of electrically switching spin conduction states, advancing molecular spintronics design.

Findings

Large low-bias conductance (~2 μS) with high spin selectivity (>99.5%)

External gate voltage can switch the dominant spin conduction from up to down

Potential for chemical design of molecular spintronic devices

Abstract

Polynuclear magnetic molecules often present dense transmission spectra with many overlapping conduction spin channels. Single-metal complexes display a sparser density of states, which in the presence of a fixed external magnetic field makes them interesting candidates for spin filtering. Here we perform a DFT study of a family of bis- and tris-dithiolate vanadium complexes sandwiched between Au(111) electrodes and demonstrate that [VO(C$_3$S$_4$O)$_2$]$^{2-}$ can behave as a dual spin filter. This means that an external stimulus can switch between the selective transmission of spin-up and spin-down carriers. By using an electrostatic gate as external stimulus we show that the onset for the spin-up conductance is at a voltage V$_g$ = -0.51 V but a small shift to V$_g$ = -0.63 V is capable of activating spin-down transport. For both cases, we estimate a large low-bias conductance (approx. 2 {\mu}S at Vbias < 50 mV) with excellent spin selectivity (> 99.5%). We conclude by commenting on the general molecular requirements for the chemical design of further such spintronics components.