Abstract

In 1935, Erwin Schrödinger put forward his famous gedanken experiment in which a microscopic degree of freedom – the emission state of a radioactive atom – and a macroscopic, classical state – the life or death of a cat – are entangled [1]. The resulting state is dubbed a Schrödinger-cat state. According to quantum theory, a measurement of the atom in a superposition basis projects the cat into a macroscopic superposition of being alive and dead. Here, we use coherent laser fields with different optical phases as a macroscopic model system and generate entangled Schrödinger-cat states in a deterministic way [3]. We reflect the coherent pulses from an optical cavity that contains a single strongly-coupled atom. This entangles the spin of the atom with the optical phase of the light field [2]. By manipulating and detecting the atomic state, we create a plethora of flying optical coherent-state superpositions. We reconstruct the corresponding Wigner functions (see Fig. 1) to demonstrate the tunability and non-classicality of the produced light state.

© 2019 IEEE