Hot Schr\"odinger Cat States
Abstract
The observation of quantum phenomena often necessitates sufficiently pure states, a requirement that can be challenging to achieve. In this study, our goal is to prepare a non-classical state originating from a mixed state, utilizing dynamics that preserve the initial low purity of the state. We generate a quantum superposition of displaced thermal states within a microwave cavity using only unitary interactions with a transmon qubit. We measure the Wigner functions of these ``hot'' Schr\"odinger cat states for an initial purity as low as 0.06. This corresponds to a cavity mode temperature of up to 1.8 Kelvin, sixty times hotter than the cavity's physical environment. Our realization of highly mixed quantum superposition states could be implemented with other continuous-variable systems e.g. nanomechanical oscillators, for which ground-state cooling remains challenging.
Cite
@article{arxiv.2406.03389,
title = {Hot Schr\"odinger Cat States},
author = {Ian Yang and Thomas Agrenius and Vasilisa Usova and Oriol Romero-Isart and Gerhard Kirchmair},
journal= {arXiv preprint arXiv:2406.03389},
year = {2025}
}
Comments
Accepted version