Cat state

In quantum mechanics, the cat state, named after Schrödinger's cat, refers to a quantum state. Generalizing Erwin Schrödinger's thought experiment, a cat state is a quantum superposition of two macroscopically distinct states. A cat state could be of one or more modes or particles, yet not necessarily an entangled state. Such cat states have been experimentally realized in various ways and at various scales.

The most common example of a cat state is the superposition of two coherent states of a single optical mode of light. These states are of special interest for the development of quantum computing.