Year: 2022
Type: article
Abstract: Microwave technology plays a central role in current wireless communications, including mobile communication and local area networks. The microwave range shows relevant advantages with respect to other frequencies in open-air transmission, such as low absorption losses and low-energy consumption, and in addition, it is the natural working frequency in superconducting quantum technologies. Entanglement distribution between separate parties is at the core of secure quantum communications. Therefore, understanding its limitations in realistic open-air settings, especially in the rather unexplored microwave regime, is crucial for transforming microwave quantum communications into a mainstream technology. Here, we investigate the feasibility of an open-air entanglement distribution scheme with microwave two-mode squeezed states. First, we study the reach of direct entanglement transmission in open air, obtaining a maximum distance of approximately 500 m with parameters feasible for state-of-the-art experiments. Subsequently, we adapt entanglement distillation and entanglement swapping protocols to microwave technology in order to reduce the environment-induced entanglement degradation. The employed entanglement distillation helps to increase quantum correlations in the short-distance low-squeezing regime by up to $46\mathrm{%}$, and the reach of entanglement increases by $14\mathrm{%}$ with entanglement swapping. Importantly, we compute the fidelity of a continuous-variable quantum teleportation protocol using open-air-distributed entanglement as a resource. Finally, we adapt this machinery to explore the limitations of quantum communication between satellites, where the impact of thermal noise is substantially reduced and diffraction losses are dominant.
Source: Physical Review Applied
Institutions: University of the Basque Country, University of Lisbon, National Statistical Institute of Portugal, Instituto Superior Técnico, Bavarian Academy of Sciences and Humanities, Walther Meissner Institute, Technical University of Munich, University of Calgary, IQM (Finland), VTT Technical Research Centre of Finland, Aalto University, Centro de Fisíca e Engenharia de Materiais Avançados, Munich Center for Quantum Science and Technology, Ikerbasque, Basque Center for Applied Mathematics
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: bronze
Funders: Deutsche Forschungsgemeinschaft, Academy of Finland, Bundesministerium für Bildung und Forschung, Eusko Jaurlaritza, Jane ja Aatos Erkon Säätiö, Ministerio de Ciencia e Innovación, Teknologiateollisuuden 100-Vuotisjuhlasäätiö, Basque Center for Applied Mathematics, QuantERA, Horizon 2020 Framework Programme, European Research Council, Fundação para a Ciência e a Tecnologia, European Regional Development Fund, Elitenetzwerk Bayern, Agencia Estatal de Investigación, H2020 European Research Council
Awards: G1175115578, A designar, G1338257350, G1622782223, G1633674249, Finnish Centre of Excellence in Quantum Technology, G1768993395, G1778906655, G2026970443, G2144570049, G2170229132, G2262748287, G2628364946, G2713276326, G2756433129, G2861357542, G2942266459, G300979063, G308504231, G3161602516, G3264862803, Instituto de Telecomunicações, G34346518, G3480869486, G3724784450, G3777950849, G3783317134, Centro de Física e Engenharia de Materiais Avançados, G3850789590, G3987967833, G4013827928, G410571670, G425668148, G4484594549, G451917667, G4626267205, G4710139657, G495187929, G5080475149, G5454278309, G55232499, G5539308778, G5626415528, Quantum Environment Engineering for Steered Systems, G5724657902, G5967599077, G6125537131, G6351756048, Controlo Quântico Independente de Modelos Teóricos, G6604905309, G683931746, G686263596, G7084143925, G7110394189, G7171623445, G7421034968, G7436716198, G7502487667, G751615522, G785050907, G7862377184, G8045666043, G8288520819, EXC 2111: Munich Center for Quantum Science and Technology (MCQST), G883709560, G8939903727, Projekt: Speicherung von Mikrowellen-Quanten-Token in Elektronen- und Kernspinensemblen - QuaMToMe -, G8957829834, G929308097
OpenAlex ID: W4221157601