In recent years, advancements in optically levitated nanoparticles have
enabled the cooling of their center-of-mass motion to the quantum ground
state. As a result, a nanoparticle, which comprises billions of atoms,
becomes delocalized over picometer scales. This talk aims to explore the
challenges and requirements of achieving a macroscopic quantum
superposition of a nanoparticle, in which the center-of-mass position is
delocalized over orders of magnitude larger scales. We will discuss an
experimentaly feasible approach that employs fast quantum dynamics in
nonharmonic potentials to meet the stringent requirements imposed by
environmentally-induced decoherence. The generation of such macroscopic
quantum states would test quantum mechanics at unprecedented scales,
develop highly sensitive detectors of external signals, and address
fundamental questions, such as the nature of the gravitational field
generated by a delocalized mass source.