  Mesoscopic quantum superpositions, or Schr\"odinger cat states, are widely
studied for fundamental investigations of quantum measurement and decoherence
as well as applications in sensing and quantum information science. The
generation and maintenance of such states relies upon a balance between
efficient external coherent control of the system and sufficient isolation from
the environment. Here we create a variety of cat states of a single trapped
atom's motion in a harmonic oscillator using ultrafast laser pulses. These
pulses produce high fidelity impulsive forces that separate the atom into
widely-separated positions, without restrictions that typically limit the speed
of the interaction or the size and complexity of the resulting motional
superposition. This allows us to quickly generate and measure cat states larger
than previously achieved in a harmonic oscillator, and create complex
multi-component superposition states in atoms.
