China

&quot;One of the promising technical solutions to improve qubit lifetimes is a logical qubit comprised of a Josephson junction located inside of a high Q-factor 3D superconducting cavity. Niobium superconducting cavities used in particle accelerators are able to reach quality factors of ~1e10, potentially enabling storage times approaching seconds. RadiaBeam is presently developing a 3D quarter-wave resonator (QWR) with shape optimized for operation in the quantum regime. This program includes several important steps: development of a QWR cavity with the optimal shape to increase the Q-factor by adopting surface treatment techniques from accelerating cavities; demonstration of the performance of a multi-qubit system with Josephson junctions, and improvement of fabrication techniques to reduce the complexity and costs of the system. The activities for most of the objectives are already ongoing. For example, we recently developed a resonator with the improved shape, machined it out of niobium, and tested it at a temperature of 10 mK. Other ongoing work includes the study of niobium surface treatments, and the use of advanced fabrication techniques such as additive manufacturing (AM), stamping, and hydro- or electro-hydraulic forming. In this paper, we will discuss the current and future fabrication activities of qubit cavities at RadiaBeam.
&quot;
![](https://assets.underline.io/uploads/markdown_image/1/image/7f2315a9324b7f771d2b010b7639c22a.png)

Quantum 2020

Fabrication approaches to 3D superconducting qubit resonators with a high Q-factor

superconducting

qubit

resonators

The Institute of Physics and IOP Publishing, in partnership with the Chinese Physical Society (CPS) and the University of Science and Technology of China (USTC) are proud to have brought together the international quantum science community online for this inaugural conference.


Early career and leading researchers from universities, industry and government worldwide came together to share, learn and collaborate on the latest research and emerging areas of high interest across quantum science and technology. The broad themes covered by Quantum 2020 included:

Quantum communication;
Quantum computing and quantum simulation;
Quantum sensing, metrology and imaging;
Quantum information theory, software and algorithms;
Quantum foundations;
Quantum technology in industry.
The four-day event featured talks from world-renowned scientists, interactive poster sessions and two exciting panel discussions on the themes of Quantum Technology in Industry and Quantum Technology Programmes Around the World.


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If you have a ticket and are experiencing problems in accessing the event, please contact us. 

The Institute of Physics and IOP Publishing, in partnership with the Chinese Physical Society (CPS) and the University of Science and Technology of China (USTC) are proud to have brought together the international quantum science community online for this inaugural conference.

Early career and leading researchers from universities, industry and government worldwide came together to share, learn and collaborate on the latest research and emerging areas of high interest across quantum science and technology. 

"One of the promising technical solutions to improve qubit lifetimes is a logical qubit comprised of a Josephson junction located inside of a high Q-factor 3D superconducting cavity. Niobium superconducting cavities used in particle accelerators are able to reach quality factors of ~1e10, potentially enabling storage times approaching seconds. RadiaBeam is presently developing a 3D quarter-wave resonator (QWR) with shape optimized for operation in the quantum regime. This program includes several important steps: development of a QWR cavity with the optimal shape to increase the Q-factor by adopting surface treatment techniques from accelerating cavities; demonstration of the performance of a multi-qubit system with Josephson junctions, and improvement of fabrication techniques to reduce the complexity and costs of the system. The activities for most of the objectives are already ongoing. For example, we recently developed a resonator with the improved shape, machined it out of niobium, and tested it at a temperature of 10 mK. Other ongoing work includes the study of niobium surface treatments, and the use of advanced fabrication techniques such as additive manufacturing (AM), stamping, and hydro- or electro-hydraulic forming. In this paper, we will discuss the current and future fabrication activities of qubit cavities at RadiaBeam.
"
![](https://assets.underline.io/uploads/markdown_image/1/image/7f2315a9324b7f771d2b010b7639c22a.png)

technical paper

Alkali and Alkaline Earth Metal Salts of cyclic N4x– Anions, where x = 1, 2 and 3: a First-Principles Crystal Structure Prediction Sergey V. Bondarchuk A recent study of binary MgxNy systems proved that nature is much more inventive than any human imagination [1]. It was found that N4 species can be recovered to ambient conditions in the form of syn-N44– anions in Mg2N4. We have studied recoverability of other similar anions, including syn- and anti-N42–, and found that these are unstable at ambient conditions. Meanwhile, the cyclic form of N4 (tetrazete, c-N4), appeared to be dynamically, mechanically and thermally stable in crystalline form at ambient conditions, that follows from our first-principles crystal structure prediction and ab initio molecular dynamics simulations. Moreover, metal salts of c-N4x– with several alkali and alkaline earth metals are found to be stable in a wide range of oxidation states (x = 1, 2 and 3). Thus, crystal structures of the following salts were predicted and their properties were studied. Depending on both nature of the metal cation and stoichiometry, these demonstrate a wide scattering in properties, namely, band gap, bulk modulus, enthalpy of formation, etc. Thus, further study of such salts is of great importance. References: [1] Laniel D, Winkler B, Koemets E, Fedotenko T, Bykov M, Bykova E, Dubrovinsky L and Dubrovinskaia N 2019 Nat. Commun. 10 451.

Alkali and Alkaline Earth Metal Salts of cyclic N4x– Anions, where x = 1, 2 and 3: a First-Principles Crystal Structure Prediction

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Alkali and Alkaline Earth Metal Salts of cyclic N4x– Anions, where x = 1, 2 and 3: a First-Principles Crystal Structure Prediction

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