Entangling Schrödinger’s cat states by bridging discrete- and continuous-variable encoding
Abstract In quantum information processing, two primary research directions have emerged: one based on discrete variables (DV) and the other on the structure of quantum states in a continuous-variable (CV) space. Integrating these two approaches could unlock new potentials, overcoming their respecti...
Saved in:
| Main Authors: | , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2025-02-01
|
| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-025-56503-8 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1823861803697831936 |
|---|---|
| author | Daisuke Hoshi Toshiaki Nagase Sangil Kwon Daisuke Iyama Takahiko Kamiya Shiori Fujii Hiroto Mukai Shahnawaz Ahmed Anton Frisk Kockum Shohei Watabe Fumiki Yoshihara Jaw-Shen Tsai |
| author_facet | Daisuke Hoshi Toshiaki Nagase Sangil Kwon Daisuke Iyama Takahiko Kamiya Shiori Fujii Hiroto Mukai Shahnawaz Ahmed Anton Frisk Kockum Shohei Watabe Fumiki Yoshihara Jaw-Shen Tsai |
| author_sort | Daisuke Hoshi |
| collection | DOAJ |
| description | Abstract In quantum information processing, two primary research directions have emerged: one based on discrete variables (DV) and the other on the structure of quantum states in a continuous-variable (CV) space. Integrating these two approaches could unlock new potentials, overcoming their respective limitations. Here, we show that such a DV–CV hybrid approach, applied to superconducting Kerr parametric oscillators (KPOs), enables us to entangle a pair of Schrödinger’s cat states by two methods. The first involves the entanglement-preserving conversion between Bell states in the Fock-state basis (DV encoding) and those in the cat-state basis (CV encoding). The second method implements a $$\sqrt{{{{\rm{iSWAP}}}}}$$ iSWAP gate between two cat states following the procedure for Fock-state encoding. This simple and fast gate operation completes a universal quantum gate set in a KPO system. Our work offers powerful applications of DV–CV hybridization and marks a first step toward developing a multi-qubit platform based on planar KPO systems. |
| format | Article |
| id | doaj-art-5611a8c629014e15981fbfb704a14974 |
| institution | Kabale University |
| issn | 2041-1723 |
| language | English |
| publishDate | 2025-02-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Nature Communications |
| spelling | doaj-art-5611a8c629014e15981fbfb704a149742025-02-09T12:45:10ZengNature PortfolioNature Communications2041-17232025-02-0116111010.1038/s41467-025-56503-8Entangling Schrödinger’s cat states by bridging discrete- and continuous-variable encodingDaisuke Hoshi0Toshiaki Nagase1Sangil Kwon2Daisuke Iyama3Takahiko Kamiya4Shiori Fujii5Hiroto Mukai6Shahnawaz Ahmed7Anton Frisk Kockum8Shohei Watabe9Fumiki Yoshihara10Jaw-Shen Tsai11Department of Physics, Graduate School of Science, Tokyo University of ScienceDepartment of Physics, Graduate School of Science, Tokyo University of ScienceResearch Institute for Science and Technology, Tokyo University of ScienceDepartment of Physics, Graduate School of Science, Tokyo University of ScienceDepartment of Physics, Graduate School of Science, Tokyo University of ScienceDepartment of Physics, Graduate School of Science, Tokyo University of ScienceRIKEN Center for Quantum Computing (RQC)Department of Microtechnology and Nanoscience, Chalmers University of TechnologyDepartment of Microtechnology and Nanoscience, Chalmers University of TechnologyResearch Institute for Science and Technology, Tokyo University of ScienceDepartment of Physics, Graduate School of Science, Tokyo University of ScienceRIKEN Center for Quantum Computing (RQC)Abstract In quantum information processing, two primary research directions have emerged: one based on discrete variables (DV) and the other on the structure of quantum states in a continuous-variable (CV) space. Integrating these two approaches could unlock new potentials, overcoming their respective limitations. Here, we show that such a DV–CV hybrid approach, applied to superconducting Kerr parametric oscillators (KPOs), enables us to entangle a pair of Schrödinger’s cat states by two methods. The first involves the entanglement-preserving conversion between Bell states in the Fock-state basis (DV encoding) and those in the cat-state basis (CV encoding). The second method implements a $$\sqrt{{{{\rm{iSWAP}}}}}$$ iSWAP gate between two cat states following the procedure for Fock-state encoding. This simple and fast gate operation completes a universal quantum gate set in a KPO system. Our work offers powerful applications of DV–CV hybridization and marks a first step toward developing a multi-qubit platform based on planar KPO systems.https://doi.org/10.1038/s41467-025-56503-8 |
| spellingShingle | Daisuke Hoshi Toshiaki Nagase Sangil Kwon Daisuke Iyama Takahiko Kamiya Shiori Fujii Hiroto Mukai Shahnawaz Ahmed Anton Frisk Kockum Shohei Watabe Fumiki Yoshihara Jaw-Shen Tsai Entangling Schrödinger’s cat states by bridging discrete- and continuous-variable encoding Nature Communications |
| title | Entangling Schrödinger’s cat states by bridging discrete- and continuous-variable encoding |
| title_full | Entangling Schrödinger’s cat states by bridging discrete- and continuous-variable encoding |
| title_fullStr | Entangling Schrödinger’s cat states by bridging discrete- and continuous-variable encoding |
| title_full_unstemmed | Entangling Schrödinger’s cat states by bridging discrete- and continuous-variable encoding |
| title_short | Entangling Schrödinger’s cat states by bridging discrete- and continuous-variable encoding |
| title_sort | entangling schrodinger s cat states by bridging discrete and continuous variable encoding |
| url | https://doi.org/10.1038/s41467-025-56503-8 |
| work_keys_str_mv | AT daisukehoshi entanglingschrodingerscatstatesbybridgingdiscreteandcontinuousvariableencoding AT toshiakinagase entanglingschrodingerscatstatesbybridgingdiscreteandcontinuousvariableencoding AT sangilkwon entanglingschrodingerscatstatesbybridgingdiscreteandcontinuousvariableencoding AT daisukeiyama entanglingschrodingerscatstatesbybridgingdiscreteandcontinuousvariableencoding AT takahikokamiya entanglingschrodingerscatstatesbybridgingdiscreteandcontinuousvariableencoding AT shiorifujii entanglingschrodingerscatstatesbybridgingdiscreteandcontinuousvariableencoding AT hirotomukai entanglingschrodingerscatstatesbybridgingdiscreteandcontinuousvariableencoding AT shahnawazahmed entanglingschrodingerscatstatesbybridgingdiscreteandcontinuousvariableencoding AT antonfriskkockum entanglingschrodingerscatstatesbybridgingdiscreteandcontinuousvariableencoding AT shoheiwatabe entanglingschrodingerscatstatesbybridgingdiscreteandcontinuousvariableencoding AT fumikiyoshihara entanglingschrodingerscatstatesbybridgingdiscreteandcontinuousvariableencoding AT jawshentsai entanglingschrodingerscatstatesbybridgingdiscreteandcontinuousvariableencoding |