Abstract

After theoretical discovery of magnetic vortices by Abrikosov, which received 2003 Nobel Prize in Physics, vortex pinning in type II superconductors has been an important topic of research for high critical current densities in applied magnetic fields desired for a variety of applications in electric and electronic devices and systems. The small vortex core size of a few nanometer comparable to the coherence length in high temperature superconductors (HTSs) has prompted an intensive research in development of nanoscale artificial pinning centers (APCs) in so-called HTS nanocomposites. Exciting results of much enhanced in-field critical current densities and pinning force densities have been achieved. This talk intends to highlight the progress made recently in HTS nanocomposites towards controllable generation of APCs with desired morphologies, dimension, concentration, and pinning efficiency for targeted applications. The future research in HTS nanocomposites to meet the need of practical applications will also be discussed.

Abstract

Until recently, the evidence for black holes had only been obtained indirectly; however, a large black hole consisting of 6.5 billion solar masses and residing 55 million light-years away has now been imaged using superconducting detectors. This was a remarkable and common-culture captivating discovery requiring an “integrated telescope” collecting measurements from many radio astronomy observatories and an international cast of collaborating scientists and engineers. This discovery could not have been accomplished without the Superconducting Insulating Superconducting (SIS) detectors at the heart of every receiver that greeted each photon after its long journey through the heavens. Four of the observatories, and almost all of the 230 GHz detectors involved in this discovery, used SIS mixer chips that were fabricated at the University of Virginia Microfabrication Laboratories (UMVL) and developed in collaboration with the National Radio Astronomy Observatory’s (NRAO) Central Development Laboratory. Decades of technology development, encompassing the materials, devices, and circuits for the detectors, was truly an effort and success by the entire superconductivity community. Imaging this black hole is just one of many scientific successes that superconductivity has enabled and several other astronomical discoveries will be highlighted in this talk.

Abstract

Superconducting qubits are coherent artificial atoms assembled from electrical circuit elements and microwave optical components. Their lithographic scalability, compatibility with microwave control, and operability at nanosecond time scales all converge to make the superconducting qubit a highly attractive candidate for the constituent logical elements of a quantum information processor. Over the past decade, spectacular improvements in the manufacturing and control of these devices have moved the superconducting qubit modality from the realm of scientific curiosity to the threshold of technical reality. In this talk, we present the progress, challenges, and opportunities ahead in the engineering of superconducting quantum computers.

Abstract

Over the past 50 years, the development of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) technologies at intermediate and high magnetic fields have revolutionized the non-invasive interrogation of biomolecules and organisms, respectively. In this overview talk, I will highlight the basic physical and chemical principles underlying the techniques, their magnet field dependencies, and current state-of-the-art applications using commercial NMR and MRI instrumentation in research lab and clinical settings. I will then discuss what can be gained with moving these techniques to ultrahigh magnetic fields as well as the challenges posed beyond maintaining persistent, homogenous magnetic fields when moving to ultrahigh magnetic fields and resonant frequencies. A particular focus of my talk will be the merging of NMR and MRI techniques as large-bore persistent magnets enter the magnetic field regime already under exploration via powered magnets and/or small-bore superconducting magnets made using conventional high-temperature superconductors.

More information provided here.

Abstract

IEEE Council on Superconductivity President Bruce Strauss hosts the virtual awards ceremony which includes acceptance speeches from the 2020 award recipients: Pasquale Fabbricatore, Akira Fujimaki, Martin Rupich, Yasuhiro Iijima, and Elie Track. In addition to the Councils' technical and service awards, the ceremony recognizes the 2020 IEEE CSC Fellow, Akihiko Kandori, and the Graduate Study Fellowship in Applied Superconductivity recipients.

Also included is a special recognition of Outgoing President Bruce Strauss given by the Council's President-Elect, John Przybysz.

Abstract

Understanding the human brain is one of the major scientific challenge of this century. Magnetic resonance imaging (MRI) is one of the most powerful tools for exploring the brain. Increasing sensitivity and spatial, temporal and spectral resolution through higher magnetic fields will help develop new tools in health care to detect and monitor psychiatric and neurodegenerative diseases. It will also contribute to expanding our knowledge in neuroscience by providing information on the structures and functions of the human brain. To this end, a new 11.7 T whole-body MRI magnet reached its nominal field in July 2019 at the CEA Paris-Saclay Neurospin Centre. This magnet, the largest MRI magnet in the world to date, is part of the Iseult/Inumac project, a French-German initiative focusing on very high field molecular imaging. It is an actively shielded magnet made from an NbTi superconductor with a homogeneous field level of 11.75 T in a 90 cm warm bore. It operates at a current of 1483 A in a pressurized bath of superfluid LHe at 1.8 K. The stored energy is 338 MJ and the inductance 308 H. The size is about 5 m in diameter and 5 m in length for a total weight of the magnet of 132 tons. The complete MRI system, including gradient and RF coils, will be commissioned in spring 2020. Here we will describe the technical challenges and breakthroughs made over the past 15 years to power the Iseult magnet, including a comparison with existing systems and future projects at higher fields. We will also briefly describe the scientific prospects for brain MRI research, as well as the possible long-term impact envisioned by the use of the Iseult MRI system.

Abstract

"ITER has now reached the stage where the first large magnet components have arrived on site and many more are nearing completion at manufacturing locations distributed throughout the ITER partners. Although we still have several years of challenging on-site assembly ahead, the acceptance tests on the superconducting components give us good confidence in their functionality. We have followed a very long route to get to this stage, and the superconductivity-related humps, bumps and diversions we have followed in the 32 years since the start of the project. Within this I will look at some of the blind alleys that were followed, both why they were chosen and why they were abandoned, particularly as regards materials closely associated with the superconductor. Within the chosen materials, as may be expected, not everything went smoothly and I will summarise the main superconductor-related recovery actions. I will also look at things that went right, as well as those that went wrong. I will trace the history of the innovations that were proposed, focussing particularly on materials and material processes, to see what became of them when faced with the reality of large scale industrial production.

The innovations in ITER were not just the more obvious ones of choice-of-superconductor and its critical current-field performance, but go much deeper into the design and manufacturing choices. In other words, it is not just a material problem but a material usability problem and I will show several examples where the associated design and manufacturing choices eventually turned out to be far more innovative than the original material choice. Such usability issues are not generally discovered in the material R&D phase but in the detailed magnet design phase, or even during manufacturing.

Some of the early history of ITER has similarities with the proposals now appearing for the next generation of magnetic fusion devices, the first generation of energy-producing fusion reactors. As with ITER 25 years ago, there seems in many cases a relatively large disconnect between choices for superconductors for machines presently under construction and those in the conceptual formulation stage. The arguments are (as with ITER), between two extremes of innovations that promise large cost gains, if they work, and well-qualified technology with a broad industrial supply case, assuming equally that it works as advertised. ITER magnets contain many examples of outstandingly successful development and industrialisation of innovations as well as several near-disasters in what should have been well-established industrial technology, and lessons for future decisions on the choices for the future of superconductivity in fusion can be drawn from both."

Abstract

Room-temperature superconductivity is one of the most challenging and long-standing problems in condensed-matter physics. I will discuss the significant progress reached in the field and focus on three main subjects: metallic hydrogen, super hydrides, and the perspectives to find high-Tc superconductors at moderate pressures. 

In 2014, superconductivity at 203 K was discovered in H3S at high pressure, breaking archaic paradigms on conventional superconductivity [1]. Last year, with the advancement of the field, Tc of 250 K we had been reached in a super hydride LaH10 [2-3]. The mechanism governing these exceptional superconductors is the conventional electron-phonon coupling [5]. Theoretically, predictions point out other compositions that could superconduct at temperatures as high as 470 K [6]. These record-breaking superconductors are the result of chasing of a 50 years old prediction of high-temperature superconductivity in hydrogen [7-8]. In this respect, we will present the most recent efforts on seeking for the superconducting phase of hydrogen [9]. The progress towards room temperature superconductivity is likely to be related to hydrides under pressure [5]. I will outline perspectives for high-temperature conventional superconductivity at moderate and ambient pressure which is expected from arrangements of atoms of light elements.

References
[1] Drozdov, A. P., Eremets, M. I., Troyan, I. A., Ksenofontov, V. & Shylin, S. I. Conventional superconductivity at 203 K at high pressures. Nature 525, 73 (2015).
[2] Drozdov, A. P. et al. Superconductivity at 250 K in lanthanum hydride under high pressures. Nature 569, 528 (2019).
[3] Somayazulu, M. et al, Evidence for Superconductivity above 260 K in Lanthanum Superhydride at Megabar Pressures. Phys. Rev. Lett. 122, 027001 (2019).
[4] I. Errea, F. Belli, L. Monacelli, A. Sanna, T. Koretsune, T. Tadano, R. Bianco, M. Calandra, R. Arita, F. Mauri and J. A. Flores-Livas. Quantum Crystal Structure in the 250 K Superconducting Lanthanum Hydride. Nature, (2020).
[5] J. A. Flores-Livas, L. Boeri, A. Sanna, R. Arita, M. Eremets. A Perspective on Conventional High-Temperature Superconductors at High Pressure: Methods and Materials. Review on Physics Reports (2020).
[6] Sun, Y., Lv, J., Xie, Y., Liu, H. & Ma, Y. The route to a Superconducting Phase above Room Temperature in Electron-Doped Hydride Compounds under High Pressure. Phys. Rev. Lett. 123, 097001 (2019).
[7] Ashcroft, N. W. Metallic hydrogen: A high-temperature superconductor? Phys. Rev. Lett. 21, 1748 (1968).
[8] Ashcroft, N. W. Hydrogen Dominant Metallic Alloys: High-Temperature Superconductors? Phys. Rev. Lett. 92, 187002 (2004).
[9] Eremets, M. I., Drozdov, A. P., Kong, P. P. & Wang, H. Semimetallic molecular hydrogen at a pressure above 350 GPa. Nature Physics, 15, 1246 (2019).

Abstract

Federico Scurti invented the SMART Conductor which are optical fibers embedded within superconducting wiring that monitor for failures in High-Temperature Superconductor systems. He also created optical fibers with increased thermal sensitivity at cryogenic temperatures.

Abstract

Dr. Gargini provides an overview of the development of semiconductor technology roadmaps and their recent evolution to encompass other materials (including superconductors), as well as other aspects including architecture, algorithms, software, and applications. He also discusses parameters related to the growing field for quantum computing.

Abstract

Dr. Holmes reprises some of the background about the semiconductor technology roadmaps evolving recently into the "International Roadmap for Devices and Systems" (IRDS) and how technologies based on cryogenics and superconductors have become part of IRDS with a dedicated chapter being prepared by the researchers and engineers in this field and how it will be updated in years to come.

Abstract

In this video, a panel discussion moderated by Dr. Scott Holmes examines the view of panelists on the status and prospects for cryogenics-based and superconductivity-based technologies for computation, information, communication, including quantum computing.

The panelists are:

• Nancy Missert (Sandia) - Josephson junction barriers for Cryoelectronics
• Pascal Febvre (University Savoie Mont Blanc, France) - Going below 90 nm
• D. Scott Holmes (Booz Allen Hamilton, USA) - SCE Foundry
• Michael P. Frank (Sandia) - Improved superconducting logic families - (asynchronous, ballistic, reversible, etc.) a difficult engineering challenge for SCE
• John Spargo (Northrop-Grumman) - importance of applications, competitiveness with other technologies, and manufacturing
• Deep Gupta (Hypres) - importance of a gradual introduction of proven products with progressively increasing complexity and of integrating different technologies in the same system
• Oleg Mukhanov (Hypres - SeeQC) - Challenges for the Roadmap - importance of scaling and density for competitiveness with alternative technologies, including 3-D integration and innovative Josephson junction configurations

Abstract

The observations of gravitational waves from the mergers of compact binary sources opens a new way to learn about the universe as well as to test General Relativity in the limit of strong gravitational interactions – the dynamics of massive bodies traveling at relativistic speeds in a highly curved space-time. The lecture will describe some of the difficult history of gravitational waves proposed about 100 years ago. The concepts used in the instruments and the methods for data analysis that enable the measurement of gravitational wave strains of 10-21 and smaller will be presented. The results derived from the measured waveforms, their relation to the Einstein field equations and the astrophysical implications are discussed. The talk will end with a vision for the future of gravitational wave astronomy.

Abstract

Numerous astrophysical measurements indicate that much of our universe is made of an undiscovered type of matter, termed 'Dark Matter'. The axion is a hypothetical particle that is a well-motivated candidate for dark matter inspired by the Peccei-Quinn solution to the Strong-CP problem in Nuclear Physics. After decades of work, the US DOE flagship axion dark matter search, ADMX G2, is the first experiment to be sensitive to plausible DFSZ coupling model of dark matter axions, in part due to the addition of superconducting quantum-limited amplifiers. ADMX G2 has begun to search the theoretically-favored axion mass region 2-40 micro-eV, and could now discover dark matter at any time.

Abstract

This presentation provides a survey of the activities in quantum computing research and development in the United States, including those carried in academic institutions, industrial research laboratories, as well as government research laboratories.

Abstract

The flagship initiative in Europe is boosting excellent research results in areas like quantum secure communication, quantum sensing, and quantum simulation and computing into concrete technological opportunities that can be taken up by industry. Quantum technologies ultimately are expected to enable solutions which address grand challenges in such fields as energy, health, security and the environment. Some are already starting to be commercially exploited. Others may still require years of fundamental research and development. The presentation gives a survey of the objectives and activities in Europe in the context of the quantum flagship covering all topics but emphasizing those based on superconducting materials and devices.

Abstract

Quantum annealing (QA) is a quantum algorithm that can be realized at-scale using existing superconducting circuit fabrication technologies and it can be applied to a wide range of commercially-relevant computation problems. State-of-the-art QA processors contain an amalgamation of single flux quantum (SFQ)-based digital circuits, high bandwidth microwave components, and flux qubits, thus employing a wide range of superconducting devices for a common purpose. Lessons learned from this effort are expected to have significant practical implications for the broader scope of future superconducting-based quantum technologies beyond QA. This lecture consists of a brief review of current state-of-the-art QA technology, a comparison of today's QA technology to other nascent quantum computing implementations, and a survey of efforts that are underway to realize next-generation QA-related technologies using superconducting circuits.

Abstract

In this talk, I will first give an overview of Chinese government Quantum information programs and then will focus on quantum computing. I will briefly introduce the main target of quantum computing in the next few years in China. As superconducting quantum computing has become one of the most promising candidates, more details of it will be shown, including our recent main signs of progress in the superconducting multi-qubit system, the next five-year plan, the funding, and the Commercial partner.

Abstract

We will give an overview of research activities on superconducting quantum computing in Japan. We will also present our approach toward integrated superconducting qubit platforms for quantum computing.