[{"project":[{"grant_number":"F07105","name":"QUANTUM INFORMATION SYSTEMS BEYOND CLASSICAL CAPABILITIES / P5- Integration of Superconducting Quantum Circuits","_id":"bdb108fd-d553-11ed-ba76-83dc74a9864f"}],"acknowledgement":"We thank Wenchao Ge and Allison Carter for feedback on the manuscript. We also thank Wenchao Ge for sharing the numerical simulation data that we have used in Fig. 5 of this paper. N.N. would like to thank Perimeter Institute and Boston University for support during this research. S.H. acknowledges partial support from the Institute of Science and Technology Austria and the Austrian Science Fund (FWF) DOI 10.55776/F71 for the duration of this project. This work was supported by DOE Quantum Systems Accelerator, ARO W911NF24-1-0128, and NSF JILA-PFC PHY-2317149. J.J.B. and A.M.R. acknowledge support through AFOSR Grant No. FA9550-25-1-0080. A.S. acknowledges support by the Department of Science and Technology, Govt. of India through the INSPIRE Faculty Award (DST/INSPIRE/04/2023/001486), by the Anusandhan National Research Foundation (ANRF), Govt. of India through the Prime Minister’s Early Career Research Grant (PMECRG) (ANRF/ECRG/2024/001160/PMS) and by IIT Madras through the New Faculty Initiation Grant (NFIG).","scopus_import":"1","publisher":"American Physical Society","department":[{"_id":"JoFi"},{"_id":"GradSch"}],"day":"01","publication_status":"published","article_type":"original","ddc":["530"],"language":[{"iso":"eng"}],"publication":"Physical Review Applied","oa_version":"Published Version","article_processing_charge":"Yes (via OA deal)","fulldoi":"https://doi.org/10.1103/h1m9-h3yw","month":"03","quality_controlled":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","corr_author":"1","date_created":"2026-03-15T23:01:35Z","license":"https://creativecommons.org/licenses/by/4.0/","author":[{"full_name":"Hawaldar, Samarth","first_name":"Samarth","orcid":"0000-0002-1965-4309","id":"221708e1-1ff6-11ee-9fa6-85146607433e","last_name":"Hawaldar"},{"last_name":"Nikhil","full_name":"Nikhil, N.","first_name":"N."},{"full_name":"Rey, Ana Maria","first_name":"Ana Maria","last_name":"Rey"},{"last_name":"Bollinger","first_name":"John J.","full_name":"Bollinger, John J."},{"last_name":"Shankar","first_name":"Athreya","full_name":"Shankar, Athreya"}],"has_accepted_license":"1","OA_place":"publisher","OA_type":"hybrid","oa":1,"publication_identifier":{"eissn":["2331-7019"]},"title":"Parametric amplification of spin-motion coupling in three-dimensional trapped-ion crystals","file_date_updated":"2026-03-16T09:24:53Z","external_id":{"arxiv":["2507.16741"]},"abstract":[{"text":"Three-dimensional (3D) crystals offer a route to scaling up trapped-ion systems for quantum sensing and quantum simulation applications; however, engineering coherent spin-motion couplings and effective spin-spin interactions in large crystals poses technical challenges associated with decoherence and prolonged timescales to generate appreciable entanglement. Here, we explore the possibility of speeding up these interactions in 3D crystals via parametric amplification. For this purpose, we derive a general Hamiltonian for the parametric amplification of spin-motion coupling that is broadly applicable to normal modes with motion transverse to or along the spatial extent of the crystal. Unlike in lower-dimensional crystals, we find that the ability to faithfully (uniformly) amplify the spin-spin interactions in 3D crystals depends on the physical implementation of the spin-motion coupling. We consider the light-shift gate, and the so-called phase-insensitive and phase-sensitive Mølmer-Sørensen (MS) gates, and we find that only the phase-sensitive MS gate can be faithfully amplified in general 3D crystals. We discuss a situation where nonuniform amplification can be advantageous. We also reconsider the effect of counter-rotating terms on parametric amplification and find that they are not as detrimental as previous studies suggest.","lang":"eng"}],"date_published":"2026-03-01T00:00:00Z","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"doi":"10.1103/h1m9-h3yw","_id":"21449","date_updated":"2026-04-14T09:04:08Z","type":"journal_article","status":"public","volume":25,"article_number":"034004","issue":"3","file":[{"relation":"main_file","content_type":"application/pdf","file_size":1421954,"creator":"dernst","success":1,"file_id":"21456","file_name":"2026_PhysicalReviewApplied_Hawaldar.pdf","checksum":"f0dc6a50222b778fd75cc72a28d38689","date_created":"2026-03-16T09:24:53Z","access_level":"open_access","date_updated":"2026-03-16T09:24:53Z"}],"intvolume":"        25","PlanS_conform":"1","citation":{"ama":"Hawaldar S, Nikhil N, Rey AM, Bollinger JJ, Shankar A. Parametric amplification of spin-motion coupling in three-dimensional trapped-ion crystals. <i>Physical Review Applied</i>. 2026;25(3). doi:<a href=\"https://doi.org/10.1103/h1m9-h3yw\">10.1103/h1m9-h3yw</a>","mla":"Hawaldar, Samarth, et al. “Parametric Amplification of Spin-Motion Coupling in Three-Dimensional Trapped-Ion Crystals.” <i>Physical Review Applied</i>, vol. 25, no. 3, 034004, American Physical Society, 2026, doi:<a href=\"https://doi.org/10.1103/h1m9-h3yw\">10.1103/h1m9-h3yw</a>.","chicago":"Hawaldar, Samarth, N. Nikhil, Ana Maria Rey, John J. Bollinger, and Athreya Shankar. “Parametric Amplification of Spin-Motion Coupling in Three-Dimensional Trapped-Ion Crystals.” <i>Physical Review Applied</i>. American Physical Society, 2026. <a href=\"https://doi.org/10.1103/h1m9-h3yw\">https://doi.org/10.1103/h1m9-h3yw</a>.","short":"S. Hawaldar, N. Nikhil, A.M. Rey, J.J. Bollinger, A. Shankar, Physical Review Applied 25 (2026).","apa":"Hawaldar, S., Nikhil, N., Rey, A. M., Bollinger, J. J., &#38; Shankar, A. (2026). Parametric amplification of spin-motion coupling in three-dimensional trapped-ion crystals. <i>Physical Review Applied</i>. American Physical Society. <a href=\"https://doi.org/10.1103/h1m9-h3yw\">https://doi.org/10.1103/h1m9-h3yw</a>","ista":"Hawaldar S, Nikhil N, Rey AM, Bollinger JJ, Shankar A. 2026. Parametric amplification of spin-motion coupling in three-dimensional trapped-ion crystals. Physical Review Applied. 25(3), 034004.","ieee":"S. Hawaldar, N. Nikhil, A. M. Rey, J. J. Bollinger, and A. Shankar, “Parametric amplification of spin-motion coupling in three-dimensional trapped-ion crystals,” <i>Physical Review Applied</i>, vol. 25, no. 3. American Physical Society, 2026."},"arxiv":1,"year":"2026"},{"external_id":{"arxiv":["2602.00928"]},"abstract":[{"text":"Superconducting qubits are a leading candidate for utility-scale quantum computing due to their fast gate speeds and steadily decreasing error rates. The requirement for millikelvin operating temperatures, however, creates a significant scaling bottleneck. Modular architectures using optical fiber links could bridge separate cryogenic nodes, but superconducting circuits do not have coherent optical transitions and microwave-to-optical conversion has not been shown for any non-classical photon state. In this work, we demonstrate the on-demand generation and tomographic reconstruction of itinerant single microwave photons at 8.9 GHz from a superconducting qubit. We upconvert this non-Gaussian state with a transducer added noise below 0.012 quanta and count the converted telecom photons at 193.4 THz with a signal-to-noise ratio of up to 5.1$\\pm$1.1. We characterize the trade-offs between throughput and noise, and establish a viable path toward heralded entanglement distribution and gate teleportation. Looking ahead, these results empower existing superconducting devices to take a key role in distributed quantum technologies and heterogeneous quantum systems.","lang":"eng"}],"OA_place":"repository","OA_type":"green","oa":1,"title":"Electro-optic conversion of itinerant Fock states","doi":"10.48550/arXiv.2602.00928","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"date_published":"2026-01-31T00:00:00Z","_id":"21870","date_updated":"2026-09-14T07:08:55Z","status":"public","related_material":{"record":[{"relation":"dissertation_contains","id":"21863","status":"public"}]},"type":"preprint","citation":{"mla":"Werner, Thomas, et al. “Electro-Optic Conversion of Itinerant Fock States.” <i>ArXiv</i>, doi:<a href=\"https://doi.org/10.48550/arXiv.2602.00928\">10.48550/arXiv.2602.00928</a>.","ama":"Werner T, Riyazi E, Hawaldar S, et al. Electro-optic conversion of itinerant Fock states. <i>arXiv</i>. doi:<a href=\"https://doi.org/10.48550/arXiv.2602.00928\">10.48550/arXiv.2602.00928</a>","chicago":"Werner, Thomas, Erfan Riyazi, Samarth Hawaldar, Rishabh Sahu, Georg M Arnold, Paul Falthansl-Scheinecker Paul Falthansl-Scheinecker, Jennifer A. Sánchez Naranjo, et al. “Electro-Optic Conversion of Itinerant Fock States.” <i>ArXiv</i>, n.d. <a href=\"https://doi.org/10.48550/arXiv.2602.00928\">https://doi.org/10.48550/arXiv.2602.00928</a>.","short":"T. Werner, E. Riyazi, S. Hawaldar, R. Sahu, G.M. Arnold, P.F.-S. Paul Falthansl-Scheinecker, J.A.S. Naranjo, D. Loi, L.N. Kapoor, M. Zemlicka, L. Qiu, A. Militaru, J.M. Fink, ArXiv (n.d.).","ista":"Werner T, Riyazi E, Hawaldar S, Sahu R, Arnold GM, Paul Falthansl-Scheinecker PF-S, Naranjo JAS, Loi D, Kapoor LN, Zemlicka M, Qiu L, Militaru A, Fink JM. Electro-optic conversion of itinerant Fock states. arXiv, <a href=\"https://doi.org/10.48550/arXiv.2602.00928\">10.48550/arXiv.2602.00928</a>.","ieee":"T. Werner <i>et al.</i>, “Electro-optic conversion of itinerant Fock states,” <i>arXiv</i>. .","apa":"Werner, T., Riyazi, E., Hawaldar, S., Sahu, R., Arnold, G. M., Paul Falthansl-Scheinecker, P. F.-S., … Fink, J. M. (n.d.). Electro-optic conversion of itinerant Fock states. <i>arXiv</i>. <a href=\"https://doi.org/10.48550/arXiv.2602.00928\">https://doi.org/10.48550/arXiv.2602.00928</a>"},"arxiv":1,"main_file_link":[{"open_access":"1","url":"https://doi.org/10.48550/arXiv.2602.00928"}],"ec_funded":1,"year":"2026","day":"31","department":[{"_id":"JoFi"},{"_id":"GradSch"}],"project":[{"_id":"bdadfa0d-d553-11ed-ba76-fb85edbd456a","name":"Cavity Quantum Electro Optics: Microwave photonics with nonclassical states","grant_number":"101089099"},{"name":"Integrated optical coupling for low loss electro-optic interconnects","_id":"5b807754-ab3d-11f0-914f-ff8c34502cc9","grant_number":"101248662"},{"grant_number":"899354","call_identifier":"H2020","_id":"9B868D20-BA93-11EA-9121-9846C619BF3A","name":"Quantum Local Area Networks with Superconducting Qubits"},{"name":"Cavity-Integrated Electro-Optics: Measuring, Converting and Manipulating Microwaves with Light","_id":"91aaf765-16d5-11f0-9cad-a8e7e44cccb7","grant_number":"101187231"},{"name":"NOMIS Fellowship Program","_id":"9B861AAC-BA93-11EA-9121-9846C619BF3A"},{"name":"QUANTUM INFORMATION SYSTEMS BEYOND CLASSICAL CAPABILITIES / P5- Integration of Superconducting Quantum Circuits","_id":"bdb108fd-d553-11ed-ba76-83dc74a9864f","grant_number":"F07105"}],"acknowledgement":"We thank Fritz Diorico and Onur Hosten who suggested the filter cavity design, and gave important insights about the assembly and the testing of the FabryPerot filter cavities. Ekatrina Fedotova and Diego A.\r\nLancheros Naranjo worked on the filter cavity setup in\r\nthe early stages of this work. Gustavo Wiederhecker and\r\nYiewen Chu provided insights as to the origins of the\r\nobserved optical noise and Nicola Carlon Zambon suggested using telecom filters to mitigate it further. This\r\nwork was supported by the European Research Council under grant agreement no. 101089099 (ERC CoG\r\ncQEO), and 101248662 (ERC POC CoupledEOT), the\r\nEuropean Unions Horizon 2020 research and innovation\r\nprogram under grant agreement no. 899354 (FETopen\r\nSuperQuLAN), the European Innovation Council no.\r\n101187231 (PathfinderOpen CIELO), and the Austrian\r\nScience Fund (FWF) no. F7105 (SFB BeyondC). J.F.\r\nand L.K. acknowledge support from the Horizon Europe\r\nProgram HORIZON-CL4-2022-QUANTUM-01-SGA via\r\nProject No. 101113946 OpenSuperQPlus100. A.M. acknowledges support from the NOMIS-ISTA fellowship.","scopus_import":"1","publication":"arXiv","publication_status":"draft","language":[{"iso":"eng"}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa_version":"Preprint","article_processing_charge":"No","month":"01","fulldoi":"https://doi.org/10.48550/arXiv.2602.00928","author":[{"id":"1fcd8497-dba3-11ea-a45e-c6fbd715f7c7","last_name":"Werner","orcid":"0009-0001-2346-5236","full_name":"Werner, Thomas","first_name":"Thomas"},{"id":"53322f94-5355-11ee-ae5a-ff6f81c87d51","last_name":"Riyazi","first_name":"Erfan","full_name":"Riyazi, Erfan"},{"last_name":"Hawaldar","id":"221708e1-1ff6-11ee-9fa6-85146607433e","orcid":"0000-0002-1965-4309","full_name":"Hawaldar, Samarth","first_name":"Samarth"},{"orcid":"0000-0001-6264-2162","last_name":"Sahu","id":"47D26E34-F248-11E8-B48F-1D18A9856A87","first_name":"Rishabh","full_name":"Sahu, Rishabh"},{"first_name":"Georg M","full_name":"Arnold, Georg M","id":"3770C838-F248-11E8-B48F-1D18A9856A87","last_name":"Arnold","orcid":"0000-0003-1397-7876"},{"last_name":"Paul Falthansl-Scheinecker","first_name":"Paul Falthansl-Scheinecker","full_name":"Paul Falthansl-Scheinecker, Paul Falthansl-Scheinecker"},{"full_name":"Naranjo, Jennifer A. Sánchez","first_name":"Jennifer A. Sánchez","last_name":"Naranjo"},{"first_name":"Dante","full_name":"Loi, Dante","last_name":"Loi"},{"first_name":"Lucky N.","full_name":"Kapoor, Lucky N.","last_name":"Kapoor"},{"orcid":"0009-0005-0878-3032","last_name":"Zemlicka","id":"2DCF8DE6-F248-11E8-B48F-1D18A9856A87","first_name":"Martin","full_name":"Zemlicka, Martin"},{"first_name":"Liu","full_name":"Qiu, Liu","id":"45e99c0d-1eb1-11eb-9b96-ed8ab2983cac","last_name":"Qiu","orcid":"0000-0003-4345-4267"},{"id":"d67706f8-8eb1-11ee-ad1b-9c30dfa19e0b","last_name":"Militaru","first_name":"Andrei","full_name":"Militaru, Andrei"},{"orcid":"0000-0001-8112-028X","id":"4B591CBA-F248-11E8-B48F-1D18A9856A87","last_name":"Fink","full_name":"Fink, Johannes M","first_name":"Johannes M"}],"corr_author":"1","date_created":"2026-05-12T13:58:18Z"},{"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa_version":"Published Version","article_processing_charge":"Yes","month":"07","fulldoi":"https://doi.org/10.1103/r4jt-j39w","supplementarymaterial":"yes","quality_controlled":"1","author":[{"last_name":"Andres Juanes","id":"7601fd3a-5355-11ee-ae5a-a20ca6f3cfb9","full_name":"Andres Juanes, Alejandro","first_name":"Alejandro"},{"first_name":"J.","full_name":"Agustí, J.","last_name":"Agustí"},{"orcid":"0000-0001-7641-8348","id":"2E6D040E-F248-11E8-B48F-1D18A9856A87","last_name":"Sett","first_name":"Riya","full_name":"Sett, Riya"},{"last_name":"Redchenko","id":"2C21D6E8-F248-11E8-B48F-1D18A9856A87","first_name":"Elena","full_name":"Redchenko, Elena"},{"first_name":"Lucky","full_name":"Kapoor, Lucky","last_name":"Kapoor","orcid":"0000-0001-8319-2148","id":"84b9700b-15b2-11ec-abd3-831089e67615"},{"last_name":"Hawaldar","orcid":"0000-0002-1965-4309","id":"221708e1-1ff6-11ee-9fa6-85146607433e","full_name":"Hawaldar, Samarth","first_name":"Samarth"},{"full_name":"Rabl, P.","first_name":"P.","last_name":"Rabl"},{"orcid":"0000-0001-8112-028X","last_name":"Fink","id":"4B591CBA-F248-11E8-B48F-1D18A9856A87","first_name":"Johannes M","full_name":"Fink, Johannes M"}],"has_accepted_license":"1","corr_author":"1","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"date_created":"2026-08-03T13:19:31Z","department":[{"_id":"JoFi"},{"_id":"GradSch"}],"publisher":"American Physical Society","day":"13","project":[{"grant_number":"F07105","name":"QUANTUM INFORMATION SYSTEMS BEYOND CLASSICAL CAPABILITIES / P5- Integration of Superconducting Quantum Circuits","_id":"bdb108fd-d553-11ed-ba76-83dc74a9864f"},{"name":"Cavity Quantum Electro Optics: Microwave photonics with nonclassical states","_id":"bdadfa0d-d553-11ed-ba76-fb85edbd456a","grant_number":"101089099"},{"grant_number":"COE01","_id":"92af0f81-16d5-11f0-9cad-924b22d6a876","name":"Quantum Science Austria (Fink)"}],"acknowledgement":"We thank A. Trioni and C. N. Borja for assistance in device fabrication, C. Siegele for fruitful discussions, IBM for donating the JPC used in this work, and the MIBA machine shop and the ISTA nanofabrication facility for technical support. This work was funded in part by the Austrian Science Fund (FWF) through the excellence cluster quantA 10.55776/COE1 and the SFB BeyondC 10.55776/F71, as well as the European Union—NextGenerationEU, and ISTA. J. F. and L. K. acknowledge support from the Horizon Europe Program HORIZON-CL4-2022-QUANTUM-01-SGA via Project No. 101113946 OpenSuperQPlus100, and J. F. from the European Research Council No. 101089099 (ERC CoG cQEO). J. A. acknowledges support from the QUANTERA project MOLAR with reference No. PCI2024-153449, funded by MICIU/AEI/10.13039/501100011033 and the European Union. This research is part of the Munich Quantum Valley, which is supported by the Bavarian state government with funds from the Hightech Agenda Bayern Plus.","scopus_import":"1","publication":"Physical Review X","dataavailabilitystatement":"The data that support the findings of this article are openly available  https://zenodo.org/records/19099731.","article_type":"original","publication_status":"published","ddc":["530"],"language":[{"iso":"eng"}],"researchdata_availability":"yes","PlanS_conform":"1","citation":{"ama":"Andres Juanes A, Agustí J, Sett R, et al. Distributing stationary qubit entanglement through a nonlocal squeezed reservoir. <i>Physical Review X</i>. 2026;16(3). doi:<a href=\"https://doi.org/10.1103/r4jt-j39w\">10.1103/r4jt-j39w</a>","mla":"Andres Juanes, Alejandro, et al. “Distributing Stationary Qubit Entanglement through a Nonlocal Squeezed Reservoir.” <i>Physical Review X</i>, vol. 16, no. 3, 031005, American Physical Society, 2026, doi:<a href=\"https://doi.org/10.1103/r4jt-j39w\">10.1103/r4jt-j39w</a>.","chicago":"Andres Juanes, Alejandro, J. Agustí, Riya Sett, Elena Redchenko, Lucky Kapoor, Samarth Hawaldar, P. Rabl, and Johannes M Fink. “Distributing Stationary Qubit Entanglement through a Nonlocal Squeezed Reservoir.” <i>Physical Review X</i>. American Physical Society, 2026. <a href=\"https://doi.org/10.1103/r4jt-j39w\">https://doi.org/10.1103/r4jt-j39w</a>.","short":"A. Andres Juanes, J. Agustí, R. Sett, E. Redchenko, L. Kapoor, S. Hawaldar, P. Rabl, J.M. Fink, Physical Review X 16 (2026).","ieee":"A. Andres Juanes <i>et al.</i>, “Distributing stationary qubit entanglement through a nonlocal squeezed reservoir,” <i>Physical Review X</i>, vol. 16, no. 3. American Physical Society, 2026.","ista":"Andres Juanes A, Agustí J, Sett R, Redchenko E, Kapoor L, Hawaldar S, Rabl P, Fink JM. 2026. Distributing stationary qubit entanglement through a nonlocal squeezed reservoir. Physical Review X. 16(3), 031005.","apa":"Andres Juanes, A., Agustí, J., Sett, R., Redchenko, E., Kapoor, L., Hawaldar, S., … Fink, J. M. (2026). Distributing stationary qubit entanglement through a nonlocal squeezed reservoir. <i>Physical Review X</i>. American Physical Society. <a href=\"https://doi.org/10.1103/r4jt-j39w\">https://doi.org/10.1103/r4jt-j39w</a>"},"file":[{"relation":"main_file","content_type":"application/pdf","file_size":5301241,"creator":"dernst","success":1,"file_id":"22640","file_name":"2026_PhysicalReviewX_AndresJuanes.pdf","checksum":"2bab109f975545d096c21dd72c738b6e","access_level":"open_access","date_created":"2026-08-04T05:40:41Z","date_updated":"2026-08-04T05:40:41Z"}],"DOAJ_listed":"1","das_tickbox":"1","intvolume":"        16","year":"2026","abstract":[{"lang":"eng","text":"The distribution of entanglement across distant qubits is a central challenge for the operation of scalable quantum computers and large-scale quantum networks. Existing approaches rely on deterministic state transfer, or probabilistic protocols that require active control or measurements and postselection. Here, we demonstrate a fundamentally different, fully autonomous process, where two remote qubits are entangled through their coupling to a quantum-correlated photonic reservoir. In our experiment, a Josephson parametric converter produces a Gaussian, continuous-variable entangled state of propagating microwave fields that drives two spatially separated superconducting transmon qubits into a stationary, discrete-variable entangled state. We also show how qubit tomography unlocks a direct and sensitive verification of two-mode squeezing in the microwave domain. These results establish networks of qubits interfaced with distributed continuous-variable entangled states as a powerful platform for foundational studies and quantum-technology applications."}],"OA_type":"gold","OA_place":"publisher","oa":1,"file_date_updated":"2026-08-04T05:40:41Z","publication_identifier":{"eissn":["2160-3308"]},"title":"Distributing stationary qubit entanglement through a nonlocal squeezed reservoir","volume":16,"article_number":"031005","issue":"3","doi":"10.1103/r4jt-j39w","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"date_published":"2026-07-13T00:00:00Z","_id":"22637","date_updated":"2026-09-16T07:38:20Z","status":"public","related_material":{"link":[{"relation":"press_release","description":"News on ISTA website","url":"https://ista.ac.at/en/news/quantum-bath-syncs-distant-qubits/"}]},"type":"journal_article"},{"year":"2025","intvolume":"       127","arxiv":1,"main_file_link":[{"url":"https://doi.org/10.48550/arXiv.2507.09298","open_access":"1"}],"citation":{"chicago":"Patel, Lipi, Samarth Hawaldar, Aditya Panikkar, Athreya Shankar, and Baladitya Suri. “Impedance-Engineered Josephson Parametric Amplifier with Single-Step Lithography.” <i>Applied Physics Letters</i>. AIP Publishing, 2025. <a href=\"https://doi.org/10.1063/5.0290636\">https://doi.org/10.1063/5.0290636</a>.","ama":"Patel L, Hawaldar S, Panikkar A, Shankar A, Suri B. Impedance-engineered Josephson parametric amplifier with single-step lithography. <i>Applied Physics Letters</i>. 2025;127(25). doi:<a href=\"https://doi.org/10.1063/5.0290636\">10.1063/5.0290636</a>","mla":"Patel, Lipi, et al. “Impedance-Engineered Josephson Parametric Amplifier with Single-Step Lithography.” <i>Applied Physics Letters</i>, vol. 127, no. 25, 254001, AIP Publishing, 2025, doi:<a href=\"https://doi.org/10.1063/5.0290636\">10.1063/5.0290636</a>.","apa":"Patel, L., Hawaldar, S., Panikkar, A., Shankar, A., &#38; Suri, B. (2025). Impedance-engineered Josephson parametric amplifier with single-step lithography. <i>Applied Physics Letters</i>. AIP Publishing. <a href=\"https://doi.org/10.1063/5.0290636\">https://doi.org/10.1063/5.0290636</a>","ieee":"L. Patel, S. Hawaldar, A. Panikkar, A. Shankar, and B. Suri, “Impedance-engineered Josephson parametric amplifier with single-step lithography,” <i>Applied Physics Letters</i>, vol. 127, no. 25. AIP Publishing, 2025.","ista":"Patel L, Hawaldar S, Panikkar A, Shankar A, Suri B. 2025. Impedance-engineered Josephson parametric amplifier with single-step lithography. Applied Physics Letters. 127(25), 254001.","short":"L. Patel, S. Hawaldar, A. Panikkar, A. Shankar, B. Suri, Applied Physics Letters 127 (2025)."},"status":"public","type":"journal_article","date_updated":"2026-01-12T09:57:53Z","_id":"20976","date_published":"2025-12-22T00:00:00Z","doi":"10.1063/5.0290636","issue":"25","article_number":"254001","volume":127,"publication_identifier":{"issn":["0003-6951"],"eissn":["1077-3118"]},"title":"Impedance-engineered Josephson parametric amplifier with single-step lithography","oa":1,"OA_type":"green","OA_place":"repository","abstract":[{"lang":"eng","text":"We present an experimental demonstration of an impedance-engineered Josephson parametric amplifier (IEJPA) fabricated in a single-step lithography process. Impedance-engineering is implemented using a lumped-element series LC circuit. We use a simpler lithography process where the entire device—impedance transformer and Josephson parametric amplifier (JPA)—is patterned in a single electron beam lithography step, followed by a double-angle Dolan-bridge technique for Al–AlOx–Al deposition. We observe amplification with 18 dB gain over a wide 400 MHz bandwidth centered around 5.3 GHz with added noise approaching the quantum limit, and a saturation power of −114 dBm. To accurately explain our experimental results, we extend existing theories for IEJPAs to incorporate the full sine nonlinearity of both the JPA and the transformer. Our work provides a route to simpler realization of broadband JPAs and a theoretical foundation for a regime of JPA operation that has been less explored in literature."}],"external_id":{"arxiv":["2507.09298"]},"date_created":"2026-01-11T23:01:34Z","author":[{"first_name":"Lipi","full_name":"Patel, Lipi","last_name":"Patel"},{"first_name":"Samarth","full_name":"Hawaldar, Samarth","last_name":"Hawaldar","orcid":"0000-0002-1965-4309","id":"221708e1-1ff6-11ee-9fa6-85146607433e"},{"last_name":"Panikkar","full_name":"Panikkar, Aditya","first_name":"Aditya"},{"last_name":"Shankar","full_name":"Shankar, Athreya","first_name":"Athreya"},{"last_name":"Suri","full_name":"Suri, Baladitya","first_name":"Baladitya"}],"quality_controlled":"1","fulldoi":"https://doi.org/10.1063/5.0290636","month":"12","article_processing_charge":"No","oa_version":"Preprint","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","language":[{"iso":"eng"}],"publication_status":"published","article_type":"original","publication":"Applied Physics Letters","scopus_import":"1","acknowledgement":"The authors acknowledge receiving support from the Space Technology Cell at IISc and ISRO through the project STC-0444(2022) and the Ministry of Electronics and Information Technology of the Government of India, under the centre of Excellence of Quantum Technology at the Indian Institute of Science, as well as the office of Principle Scientific Advisor, Government of India. S.H. and A.P. acknowledge the support of the Kishore Vaigyanik Protsahan Yojana (KVPY). A.S. acknowledges the support of a New Faculty Initiation Grant (NFIG) from IIT Madras.","day":"22","department":[{"_id":"JoFi"}],"publisher":"AIP Publishing"},{"ddc":["539"],"language":[{"iso":"eng"}],"publication_status":"published","article_type":"original","publication":"Physical Review Applied","scopus_import":"1","acknowledgement":"The authors acknowledge the support of DST-INSPIRE Fellowship No. IF180339 and DST-SERB Core Research Grant No. CRG/2018/002129. S.H. acknowledges the support of the Kishore Vaigyanik Protsahan Yojana (KVPY). S.H. also acknowledges helpful discussions with Harsh Arora and Johannes Fink.","isi":1,"publisher":"American Physical Society","department":[{"_id":"GradSch"},{"_id":"JoFi"}],"day":"18","date_created":"2025-04-24T06:34:07Z","corr_author":"1","has_accepted_license":"1","author":[{"id":"221708e1-1ff6-11ee-9fa6-85146607433e","last_name":"Hawaldar","orcid":"0000-0002-1965-4309","first_name":"Samarth","full_name":"Hawaldar, Samarth"},{"first_name":"Siddhi Satish","full_name":"Khaire, Siddhi Satish","last_name":"Khaire"},{"last_name":"Delsing","full_name":"Delsing, Per","first_name":"Per"},{"first_name":"Baladitya","full_name":"Suri, Baladitya","last_name":"Suri"}],"fulldoi":"https://doi.org/10.1103/physrevapplied.23.044042","quality_controlled":"1","month":"04","article_processing_charge":"Yes (via OA deal)","oa_version":"Published Version","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","type":"journal_article","status":"public","date_updated":"2025-09-30T12:17:33Z","_id":"19617","doi":"10.1103/physrevapplied.23.044042","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"date_published":"2025-04-18T00:00:00Z","article_number":"044042","issue":"4","volume":23,"file_date_updated":"2025-04-24T06:40:22Z","publication_identifier":{"issn":["2331-7019"]},"title":"On-demand single-microwave-photon source in a superconducting circuit with wideband frequency tunability","oa":1,"OA_place":"publisher","OA_type":"hybrid","abstract":[{"lang":"eng","text":"In this article, we propose a method for generating single microwave photons in superconducting circuits. We theoretically show that pure single microwave photons can be generated on demand and tuned over a large frequency band by making use of Landau-Zener transitions under a rapid sweep of a control parameter. We devise a protocol that enables fast control of the frequency of the emitted photon over two octaves, without requiring extensive calibration. Additionally, we make theoretical estimates of the generation efficiency, tunability, purity, and linewidth of the photons emitted using this method for both charge- and flux-qubit-based architectures. We also provide estimates of the optimal device parameters required for these architectures to realize the device."}],"external_id":{"isi":["001490745300002"]},"year":"2025","intvolume":"        23","file":[{"file_size":837219,"relation":"main_file","content_type":"application/pdf","creator":"shawalda","success":1,"access_level":"open_access","date_created":"2025-04-24T06:40:22Z","date_updated":"2025-04-24T06:40:22Z","file_name":"PhysRevApplied.23.044042.pdf","file_id":"19620","checksum":"582b2ed6afb654300cabf0e3add14ca8"}],"citation":{"ieee":"S. Hawaldar, S. S. Khaire, P. Delsing, and B. Suri, “On-demand single-microwave-photon source in a superconducting circuit with wideband frequency tunability,” <i>Physical Review Applied</i>, vol. 23, no. 4. American Physical Society, 2025.","ista":"Hawaldar S, Khaire SS, Delsing P, Suri B. 2025. On-demand single-microwave-photon source in a superconducting circuit with wideband frequency tunability. Physical Review Applied. 23(4), 044042.","apa":"Hawaldar, S., Khaire, S. S., Delsing, P., &#38; Suri, B. (2025). On-demand single-microwave-photon source in a superconducting circuit with wideband frequency tunability. <i>Physical Review Applied</i>. American Physical Society. <a href=\"https://doi.org/10.1103/physrevapplied.23.044042\">https://doi.org/10.1103/physrevapplied.23.044042</a>","short":"S. Hawaldar, S.S. Khaire, P. Delsing, B. Suri, Physical Review Applied 23 (2025).","chicago":"Hawaldar, Samarth, Siddhi Satish Khaire, Per Delsing, and Baladitya Suri. “On-Demand Single-Microwave-Photon Source in a Superconducting Circuit with Wideband Frequency Tunability.” <i>Physical Review Applied</i>. American Physical Society, 2025. <a href=\"https://doi.org/10.1103/physrevapplied.23.044042\">https://doi.org/10.1103/physrevapplied.23.044042</a>.","mla":"Hawaldar, Samarth, et al. “On-Demand Single-Microwave-Photon Source in a Superconducting Circuit with Wideband Frequency Tunability.” <i>Physical Review Applied</i>, vol. 23, no. 4, 044042, American Physical Society, 2025, doi:<a href=\"https://doi.org/10.1103/physrevapplied.23.044042\">10.1103/physrevapplied.23.044042</a>.","ama":"Hawaldar S, Khaire SS, Delsing P, Suri B. On-demand single-microwave-photon source in a superconducting circuit with wideband frequency tunability. <i>Physical Review Applied</i>. 2025;23(4). doi:<a href=\"https://doi.org/10.1103/physrevapplied.23.044042\">10.1103/physrevapplied.23.044042</a>"}},{"fulldoi":"https://doi.org/10.1103/PhysRevX.14.031030","quality_controlled":"1","month":"08","oa_version":"Published Version","article_processing_charge":"Yes","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","date_created":"2024-09-01T22:01:08Z","corr_author":"1","author":[{"id":"221708e1-1ff6-11ee-9fa6-85146607433e","orcid":"0000-0002-1965-4309","last_name":"Hawaldar","first_name":"Samarth","full_name":"Hawaldar, Samarth"},{"last_name":"Shahi","first_name":"Prakriti","full_name":"Shahi, Prakriti"},{"full_name":"Carter, Allison L.","first_name":"Allison L.","last_name":"Carter"},{"last_name":"Rey","full_name":"Rey, Ana Maria","first_name":"Ana Maria"},{"full_name":"Bollinger, John J.","first_name":"John J.","last_name":"Bollinger"},{"last_name":"Shankar","first_name":"Athreya","full_name":"Shankar, Athreya"}],"has_accepted_license":"1","scopus_import":"1","isi":1,"acknowledgement":"We thank M. Miskeen Khan, Jennifer Lilieholm, and Wes Johnson for a careful reading and feedback on the manuscript. We acknowledge discussions with Dan Dubin, John Zaris, and Scott Parker. S. H. acknowledges the support of Kishore Vaigyanik Protsahan Yojana, Department of Science and Technology, Government of India. A. S. acknowledges the support of a C. V. Raman post-doctoral fellowship. A. L. C., A. M. R., and J. J. B. acknowledge funding from the U.S. Department of Energy, Office of Science, NQI Science Research Centers, Quantum Systems Accelerator (QSA), a collaboration between the U.S. Department of Energy, Office of Science and other agencies. A. M. R. acknowledges additional support from VBFF, ARO Grant No. W911NF-24-1-0128, by the NSF Grants No. JILA-PFC PHY-2317149 and No. QLCI-OMA-2016244, and by NIST. J. J. B. acknowledges additional support from the DARPA ONISQ program and AFOSR Grant No. FA9550-201-0019.","publisher":"American Physical Society","department":[{"_id":"JoFi"}],"day":"16","article_type":"original","publication_status":"published","ddc":["530"],"language":[{"iso":"eng"}],"publication":"Physical Review X","intvolume":"        14","DOAJ_listed":"1","file":[{"access_level":"open_access","date_created":"2024-09-06T09:43:53Z","date_updated":"2024-09-06T09:43:53Z","file_id":"17757","file_name":"2024_PhysRevX_Hawaldar.pdf","checksum":"5d39b7dda67fd7b9a960235f6f38e280","success":1,"creator":"cchlebak","file_size":3909653,"relation":"main_file","content_type":"application/pdf"}],"arxiv":1,"citation":{"ama":"Hawaldar S, Shahi P, Carter AL, Rey AM, Bollinger JJ, Shankar A. Bilayer crystals of trapped ions for quantum information processing. <i>Physical Review X</i>. 2024;14(3). doi:<a href=\"https://doi.org/10.1103/PhysRevX.14.031030\">10.1103/PhysRevX.14.031030</a>","mla":"Hawaldar, Samarth, et al. “Bilayer Crystals of Trapped Ions for Quantum Information Processing.” <i>Physical Review X</i>, vol. 14, no. 3, 031030, American Physical Society, 2024, doi:<a href=\"https://doi.org/10.1103/PhysRevX.14.031030\">10.1103/PhysRevX.14.031030</a>.","chicago":"Hawaldar, Samarth, Prakriti Shahi, Allison L. Carter, Ana Maria Rey, John J. Bollinger, and Athreya Shankar. “Bilayer Crystals of Trapped Ions for Quantum Information Processing.” <i>Physical Review X</i>. American Physical Society, 2024. <a href=\"https://doi.org/10.1103/PhysRevX.14.031030\">https://doi.org/10.1103/PhysRevX.14.031030</a>.","short":"S. Hawaldar, P. Shahi, A.L. Carter, A.M. Rey, J.J. Bollinger, A. Shankar, Physical Review X 14 (2024).","ieee":"S. Hawaldar, P. Shahi, A. L. Carter, A. M. Rey, J. J. Bollinger, and A. Shankar, “Bilayer crystals of trapped ions for quantum information processing,” <i>Physical Review X</i>, vol. 14, no. 3. American Physical Society, 2024.","ista":"Hawaldar S, Shahi P, Carter AL, Rey AM, Bollinger JJ, Shankar A. 2024. Bilayer crystals of trapped ions for quantum information processing. Physical Review X. 14(3), 031030.","apa":"Hawaldar, S., Shahi, P., Carter, A. L., Rey, A. M., Bollinger, J. J., &#38; Shankar, A. (2024). Bilayer crystals of trapped ions for quantum information processing. <i>Physical Review X</i>. American Physical Society. <a href=\"https://doi.org/10.1103/PhysRevX.14.031030\">https://doi.org/10.1103/PhysRevX.14.031030</a>"},"year":"2024","oa":1,"publication_identifier":{"eissn":["2160-3308"]},"file_date_updated":"2024-09-06T09:43:53Z","title":"Bilayer crystals of trapped ions for quantum information processing","external_id":{"arxiv":["2312.10681"],"isi":["001293977800002"]},"abstract":[{"text":"Trapped-ion systems are a leading platform for quantum information processing, but they are currently limited to 1D and 2D arrays, which imposes restrictions on both their scalability and their range of applications. Here, we propose a path to overcome this limitation by demonstrating that Penning traps can be used to realize remarkably clean bilayer crystals, wherein hundreds of ions self-organize into two well-defined layers. These bilayer crystals are made possible by the inclusion of an anharmonic trapping potential, which is readily implementable with current technology. We study the normal modes of this system and discover salient differences compared to the modes of single-plane crystals. The bilayer geometry and the unique properties of the normal modes open new opportunities—in particular, in quantum sensing and quantum simulation—that are not straightforward in single-plane crystals. Furthermore, we illustrate that it may be possible to extend the ideas presented here to realize multilayer crystals with more than two layers. Our work increases the dimensionality of trapped-ion systems by efficiently utilizing all three spatial dimensions, and it lays the foundation for a new generation of quantum information processing experiments with multilayer 3D crystals of trapped ions.","lang":"eng"}],"date_updated":"2025-09-08T09:07:29Z","status":"public","type":"journal_article","doi":"10.1103/PhysRevX.14.031030","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"date_published":"2024-08-16T00:00:00Z","_id":"17477","article_number":"031030","issue":"3","volume":14}]