Hot Schrödinger cat states.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40184464.
- Also identified by DOI 10.1126/sciadv.adr4492 and PMC identifier 13109942.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
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 nonclassical state originating from a mixed state, using 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" Schrödinger cat states for an initial purity as low as 0.06. This corresponds to a cavity mode temperature of up to 1.8 kelvin, 60 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.