Enhancing the Formation of Wigner Negativity in a Kerr Oscillator via Quadrature Squeezing

TL;DR

This paper explores how quadrature squeezing enhances the formation of Wigner negativity in a Kerr oscillator, considering both ideal and open systems with damping and dephasing, revealing asymptotic behaviors that improve nonlinearity effects.

Contribution

It demonstrates that increasing initial state squeezing can enhance Wigner negativity in Kerr oscillators, even under damping and dephasing, providing insights for experimental quantum state engineering.

Findings

Large squeezing leads to asymptotic negativity behavior.

Damping and dephasing effects are mitigated by increased squeezing.

Weak nonlinearity benefits from higher squeezing without increased dephasing.

Abstract

Motivated by quantum experiments with nanomechanical systems, the evolution of a Kerr oscillator with focus on creation of states with a negative Wigner function is investigated. Using the phase space formalism, results are presented that demonstrate an asymptotic behavior in the large squeezing regime for the negativity of a squeezed vacuum state under unitary evolution. The analysis and model are extended to squeezed vacuum states of open systems, adding the decoherence effects of damping and dephasing. To increase experimental relevance, the regime of strong damping is considered. These effects are investigated, yielding similar asymptotic results for the behavior of these effects in the large squeezing regime. Combining these results, it is shown that a weak nonlinearity as compared to damping may be improved by increasing the squeezing of the initial state. It is also shown that this may be done without exacerbating the effects of dephasing.