high-temperature superconductivity

high-temperature superconductivity
Name	High-temperature superconductivity
Field	Condensed matter physics
First discovered	1986
Notable people	Karl Alexandre Müller; J. Georg Bednorz; Alexei Abrikosov; Philip W. Anderson; J. Robert Schrieffer
Notable institutions	IBM; University of Zurich; Bell Labs; Massachusetts Institute of Technology

Contents

high-temperature superconductivity High-temperature superconductivity is a phenomenon in which certain materials exhibit zero electrical resistance and expulsion of magnetic flux at temperatures much higher than those of conventional superconductors. The discovery in 1986 transformed research at institutions such as IBM, University of Zurich, and Bell Labs and led to rapid developments involving researchers like J. Georg Bednorz, Karl Alexandre Müller, Philip W. Anderson, and Alexei Abrikosov. Efforts span experimental programs at Massachusetts Institute of Technology, Stanford University, and Max Planck Society laboratories and theoretical work connected to concepts from BCS theory, Anderson localization, and the Hubbard model.

Introduction

High-temperature superconductivity emerged after the 1986 report by J. Georg Bednorz and Karl Alexandre Müller identifying superconductivity in a copper-oxide compound, which invigorated experimental groups at Bell Labs and theorists at Princeton University and Cambridge University. The field rapidly engaged Nobel committees such as those awarding the Nobel Prize in Physics and intersected with materials programs at the U.S. Department of Energy, collaborative projects like those at CERN, and industrial research from Siemens and General Electric. This research pathway connected historical efforts in superconductivity by figures including John Bardeen and J. Robert Schrieffer and built upon methods developed at places like Los Alamos National Laboratory and Argonne National Laboratory.

Research has focused on several material classes: copper-oxide cuprates discovered at IBM Zurich Research Laboratory and studied at Columbia University, iron-based pnictides first reported by groups linked to Max Planck Institute for Solid State Research, and more recent nickelate compounds investigated by teams at University of Tokyo and Rice University. Key cuprates include compounds related to Yttrium barium copper oxide (YBCO) studied at University of Cambridge and Harvard University and bismuth-based systems explored at Los Alamos National Laboratory. Iron pnictides have been pursued by researchers connected to Stanford University and Bell Labs and include members structurally related to LaFeAsO. Other families such as heavy-fermion superconductors investigated at University of Illinois Urbana-Champaign and organic superconductors probed at University of Tokyo broaden the materials landscape, while thin films produced at IBM and heterostructures engineered at Swiss Federal Institute of Technology in Zurich enable device-oriented studies.

Competing theories draw on models developed by researchers at Princeton University and Massachusetts Institute of Technology, including the Hubbard model and the t-J model used to describe strong correlations emphasized by Philip W. Anderson. Proposals range from spin-fluctuation mediated pairing advocated by theorists at University of Chicago to resonating valence bond ideas originating in work associated with Bell Labs and Columbia University. Methods such as dynamical mean field theory advanced at Rutgers University and numerical approaches developed at Argonne National Laboratory and Oak Ridge National Laboratory complement analytic techniques pioneered by groups at New York University and University of California, Berkeley. The debate over pairing symmetry and pseudogap phenomena has engaged communities that contributed to the Nobel Prize in Physics and reflects influences from theories like BCS theory and insights from studies associated with Los Alamos National Laboratory.

Experimental advances rely on tools established at facilities including SLAC National Accelerator Laboratory, Brookhaven National Laboratory, and synchrotron sources at European Synchrotron Radiation Facility. Techniques such as angle-resolved photoemission spectroscopy practised at Stanford Linear Accelerator Center and neutron scattering at Institut Laue-Langevin probe electronic structure and magnetic excitations in materials synthesized at Oak Ridge National Laboratory and National Institute for Materials Science. Scanning tunneling microscopy work at IBM and University of Oxford maps gap structure, while muon spin rotation experiments at Paul Scherrer Institute measure vortex behavior. Precision transport and magnetometry measurements carried out at National High Magnetic Field Laboratory and University of Tokyo quantify critical temperatures and critical fields crucial to device prospects pursued by companies like Siemens and research centers such as Fraunhofer Society.

Applied research connects discoveries to technologies investigated by General Electric, Siemens, and national projects funded by U.S. Department of Energy and European Commission. Demonstrations include fault current limiters developed with partners at ABB Group, superconducting magnets for magnetic resonance imaging systems aligned with work at Philips and Siemens Healthineers, and power transmission prototypes tested in collaborations involving National Grid (UK) and Toshiba. Quantum device concepts tie to efforts in quantum computing pursued at IBM Quantum and Google Quantum AI, leveraging Josephson junction-based circuits whose understanding traces to Nobel Prize in Physics laureates and groups at Yale University and University of California, Santa Barbara.

Outstanding challenges remain, including the microscopic pairing mechanism debated across research groups at Princeton University, Columbia University, Harvard University, and Max Planck Society; materials synthesis hurdles faced by teams at National Institute for Materials Science and University of Tokyo; and scalability for industry partners such as Siemens and General Electric. Fundamental open questions involve the nature of the pseudogap explored by collaborations linked to Brookhaven National Laboratory and the role of quantum criticality investigated at Los Alamos National Laboratory and Rutgers University. Bridging theory and application requires coordination among funding bodies like the National Science Foundation and international laboratories including CERN and KEK.