Propagating Gottesman-Kitaev-Preskill states encoded in an optical oscillator

Abstract

<p>Gottesman-Kitaev-Preskill (GKP) qubit in a single Bosonic harmonic oscillator is an efficient logical qubit for mitigating errors in a quantum computer. The entangling gates and syndrome measurements for quantum error correction only require noise-robust linear operations, a toolbox that is naturally available and scalable in optical system. To date, however, GKP qubits have been only demonstrated at mechanical and microwave frequency in a highly nonlinear stationary system. In this work, we realize a GKP state in propagating light at the telecommunication wavelength and demonstrate homodyne measurements on the GKP states without loss corrections. Our states do not only show nonclassicality and non-Gaussianity at room temperature and atmospheric pressure, but the propagating wave property also permits large-scale quantum computation with strong compatibility to telecommunication technology.</p><p>Funding provided by: Japan Society for the Promotion of Science<br>Crossref Funder Registry ID: https://ror.org/00hhkn466<br>Award Number: 23K13040</p><p>Funding provided by: Japan Society for the Promotion of Science<br>Crossref Funder Registry ID: https://ror.org/00hhkn466<br>Award Number: 21J11615</p><p>Funding provided by: Czech Science Foundation<br>Crossref Funder Registry ID: https://ror.org/01pv73b02<br>Award Number: 22-08772S</p><p>Funding provided by: Czech Science Foundation<br>Crossref Funder Registry ID: https://ror.org/01pv73b02<br>Award Number: 21-13265X</p><p>Funding provided by: Japan Science and Technology Agency<br>Crossref Funder Registry ID: https://ror.org/00097mb19<br>Award Number: JPMJPR2254</p><p>Funding provided by: Moonshot Research and Development Program<br>Award Number: JPMJMS2064</p><p>Funding provided by: Moonshot Research and Development Program<br>Award Number: JPMJMS2066</p><p>Funding provided by: UTokyo Foundation<br>Award Number: </p><p>Funding provided by: Nichia Corporation<br>Award Number: </p><p>Funding provided by: Research Foundation for OptoScience and Technology<br>Award Number: </p><p>Funding provided by: CLUSTEC<br>Award Number: 101080173</p><p>Funding provided by: EU H2020-WIDESPREAD-2020-5<br>Award Number: NONGAUSS (951737)</p><p>Funding provided by: Federal Ministry of Education and Research<br>Crossref Funder Registry ID: https://ror.org/04pz7b180<br>Award Number: </p><p>This is the data of the quadrature values of the generated states which are obtained by postprocessing of the homodyne detector data collected via oscilloscope. </p&gt