  In this work, the morphology of nematic capillary nanobridges in slit pores
separated by a vertical distance $D$ will be characterised by Monte Carlo
simulations for oblate molecules nematogen modelled by the Gay-Berne potential.
Previous studies on droplets show that the molecules are arranged
homeotropically at the nematic-vapour interface and form spherical droplets
with an annular disclination located in their equatorial plane. In the presence
of pores with attractive substrates that favour homeotropic anchoring, the
formation of nanobridges characterised by anchoring angles that decrease with
increasing particle-substrate interaction intensity is observed. When the
orientational field in the nanobridge is analysed, the formation of an annular
disclination of topological charge $+1/2$ located in the plane perpendicular to
the $z$-axis that passes through the centre of mass of the nanobridge is
observed for small $D$. However, when considering higher values of $D$, a
change to a biaxial orientational profile within the nanobridge is observed,
where now the annular disclination is arranged in a plane perpendicular to one
direction of the $xy$ plane. These results are indicative of the existence of
an orientational phase transition for an intermediate $D$ value between a
uniaxial and a biaxial orientational configuration in the capillary nanobridge.
