  Quasi one-dimensional (1D) vanadium tetrasulfide ($VS_4$) nanowires (NWs) are
synthetic semiconductors which combine with each other through Van der Waals
interactions to form bulk phases. However, the properties of these individual
nanowires remain unknown. Nevertheless, our calculations of their stability
indicate that $VS_4$) NWs can be separated from their bulk structures.
Accordingly, we theoretically investigated the geometrical, electronic, and
magnetic properties of bulk phase and isolated $VS_4$ NWs. Our results indicate
that both bulk phase and isolated $VS_4$ NWs are semiconductors with band gaps
of 2.24 and 2.64 eV, respectively, and that they prefer the antiferromagnetic
(AFM) ground state based on DFT calculations. These calculations also suggested
that isolated $VS_4$ NWs show half-metallic antiferromagnetism upon electron
and hole doping because carrier doping splits the spin degeneracy to induce
local spin polarisation. As a result, spin polarisation currents in isolated
$VS_4$ NWs can be manipulated with locally applied gate voltage. Therefore,
these 1D AFM materials have a high potential for advancing both fundamental
research and spintronic applications because they are more resistant to
magnetic perturbation than their 1D ferromagnetic counterparts.
