  Creating a massive spatial quantum superposition, such as the Schr\"odinger
cat state, where the mass and the superposition size within the range
$10^{-19}-10^{-14}$ kg and $\Delta x \sim 10~{\rm nm}-100~\mu {\rm m}$, is a
challenging task. The methods employed so far rely either on wavepacket
expansion or on a quantum ancilla, e.g. single spin dependent forces, which
scale inversely with mass. In this paper, we present a novel approach that
combines gravitational acceleration and diamagnetic repulsion to generate a
large spatial superposition in a relatively short time. After first creating a
modest initial spatial superposition of $1~\mu {\rm m}$, achieved through
techniques such as the Stern-Gerlach (SG) apparatus, we will show that we can
achieve an $\sim 10^{2}-10^{3}$ fold improvement to the spatial superposition
size ($1~{\rm \mu m}\rightarrow 980~\mu {\rm m}$) between the wave packets in
less than $0.02$~s by using the Earth's gravitational acceleration and then the
diamagnetic repulsive scattering of the nanocrystal, neither of which depend on
the object mass. Finally, the wave packet trajectories can be closed so that
spatial interference fringes can be observed. Our findings highlight the
potential of combining gravitational acceleration and diamagnetic repulsion to
create and manipulate large spatial superpositions, offering new insights into
creating macroscopic quantum superpositions.
