Generation of squeezed Schr\"odinger cat states with an operation allowing iterative growth

TL;DR

This paper demonstrates the first experimental implementation of a breeding operation for Schr"odinger cat states, enabling their iterative growth and opening new avenues for creating mesoscopic quantum states.

Contribution

It introduces a novel hybrid operation that allows the iterative growth of Schr"odinger cat states through a heralded process using Fock states and homodyne measurement.

Findings

Achieved generation of a squeezed Schr"odinger cat state with 61% fidelity.

Successfully demonstrated the breeding operation starting from Fock states.

Paved the way for creating larger mesoscopic quantum states through iteration.

Abstract

We present what is to our knowledge the first implementation of a Schr\"odinger cat states "breeding" operation, which allows an iterative growth of these states. We thus report the experimental generation of a squeezed Schr\"odinger cat state from two single photon Fock states, which can be seen as cat states with zero amplitude. These Fock states are mixed on a symmetrical beamsplitter and the generation is heralded by a homodyne measurement in one of the two output arms. The output state has a fidelity of 61% with an even squeezed Schr\"odinger cat state of amplitude $\alpha=1.63$. This hybrid operation opens up new prospects in quantum optics as the protocol depicted here can be iterated in order to produce new kind of mesoscopic states.