{"id":1758,"date":"2025-12-05T14:59:39","date_gmt":"2025-12-05T04:59:39","guid":{"rendered":"https:\/\/qo.lab.uq.edu.au\/?p=1758"},"modified":"2026-02-20T13:44:56","modified_gmt":"2026-02-20T03:44:56","slug":"paper-mechanically-mediated-optical-microwave-quantum-state-transfer-by-feedback","status":"publish","type":"post","link":"https:\/\/qo.lab.uq.edu.au\/?p=1758","title":{"rendered":"Paper: Mechanically mediated optical-microwave quantum state transfer by feedback"},"content":{"rendered":"
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05 Dec 2025<\/p>\n\n\n\n

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State transfer between light and microwaves is a key challenge in quantum networks. Promising transducers use a mechanical intermediary that couples to both fields via radiation pressure. Such electro-optomechanical devices have achieved high efficiencies, yet require resolved-sideband cavities, and generally compromise in scalability and noise performance. Here, we relax this constraint by extending the protocol of Navarathna et al. that transfers optical quantum information onto a mechanical resonator using a broadband, sideband-unresolved cavity and feedback. Combining this with parametric mechanical-to-microwave conversion, we show that continuous optical-to-microwave quantum state transfer is possible using measurement-based feedback, while all-optical coherent feedback enables bidirectional transfer. To assess the transfer, we introduce the quantum transfer witness WT<\/sub>, which — though similar to the input-referred added noise — also identifies whether a channel is capable of both preserving Gaussian entanglement and outperforming classical transduction schemes. Finally, we show that quantum-compatible noise performance is within reach of current experimental capabilities. Our results unlock a new design space for electro-optomechanical transducers and strengthens their candidacy as scalable quantum links between distant nodes.<\/p>\n\n\n\n

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Max Foreman<\/figcaption><\/figure>\n<\/div><\/div>\n\n\n\n
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Jesse Slim<\/figcaption><\/figure>\n<\/div><\/div>\n\n\n\n
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Warwick Bowen<\/figcaption><\/figure>\n<\/div><\/div>\n<\/div>\n\n\n\n
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05 Dec 2025 Abstract State transfer between light and microwaves is a key challenge in quantum networks. Promising transducers use a mechanical intermediary that couples to both fields via radiation pressure. Such electro-optomechanical devices have achieved high efficiencies, yet require resolved-sideband cavities, and generally compromise in scalability and noise performance. Here, we relax this constraint […]<\/p>\n","protected":false},"author":11,"featured_media":1766,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"cybocfi_hide_featured_image":"yes","footnotes":""},"categories":[1],"tags":[],"class_list":["post-1758","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorised"],"featured_image_src":"https:\/\/qo.lab.uq.edu.au\/wp-content\/uploads\/2026\/02\/statetransfer_feat.png","author_info":{"display_name":false,"author_link":"https:\/\/qo.lab.uq.edu.au\/?author=11"},"jetpack_featured_media_url":"https:\/\/qo.lab.uq.edu.au\/wp-content\/uploads\/2026\/02\/statetransfer_feat.png","_links":{"self":[{"href":"https:\/\/qo.lab.uq.edu.au\/index.php?rest_route=\/wp\/v2\/posts\/1758","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/qo.lab.uq.edu.au\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/qo.lab.uq.edu.au\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/qo.lab.uq.edu.au\/index.php?rest_route=\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/qo.lab.uq.edu.au\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1758"}],"version-history":[{"count":2,"href":"https:\/\/qo.lab.uq.edu.au\/index.php?rest_route=\/wp\/v2\/posts\/1758\/revisions"}],"predecessor-version":[{"id":1811,"href":"https:\/\/qo.lab.uq.edu.au\/index.php?rest_route=\/wp\/v2\/posts\/1758\/revisions\/1811"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/qo.lab.uq.edu.au\/index.php?rest_route=\/wp\/v2\/media\/1766"}],"wp:attachment":[{"href":"https:\/\/qo.lab.uq.edu.au\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1758"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qo.lab.uq.edu.au\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1758"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qo.lab.uq.edu.au\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1758"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}