The discovery that certain materials exhibit superconductivity at temperatures above 77 kelvin (minus 320 degrees Fahrenheit) in 1987 by a team of researchers at the University of Houston and the University of Alabama, led by Professor Paul C. W. Chu, now the Founding Director and Chief Scientist of the Texas Center for Superconductivity at the University of Houston (TcSUH), has been designated an IEEE Milestone in Electrical Engineering and Computing. A plaque emblematic of this designation was presented to the University of Houston at a ceremony held at the Hilton University of Houston Hotel on November 17th by Professor J. Roberto de Marca, President and CEO of the IEEE, and was accepted, on behalf of the University of Houston, by Dr. Renu Khator, Chancellor of the University of Houston System and President of the University of Houston. The plaque has been permanently mounted in the lobby area of Science Research Building One, on the University of Houston campus, where the discovery of these materials was made in 1987. The IEEE Milestones in Electrical Engineering and Computing program honors significant technical achievements in technology areas that benefit humanity. This Milestone was the 149th to be approved by the IEEE Board of Directors since the IEEE Milestone Program was established in 1983.
| Figure 1. |
Photograph of the IEEE Milestone in Electrical Engineering
and Computing plaque that was presented to the University
of Houston on November 17, 2014.
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The arrangements for the events associated with the dedication of the Milestone Plaque were made by the Texas Center for Superconductivity at the University of Houston (TcSUH), the IEEE Houston Section, and the IEEE Council on Superconductivity, and was were sponsored by the UH Division of Research, the UH Cullen College of Engineering, the UH College of Natural Sciences and Mathematics, and by the T.L.L. Temple Endowment. The proposal for the Milestone was initiated and submitted to the IEEE History Committee by Prof. Willis A. King, Emeritus Professor and Chair of the Computer Sciences Department at the University of Houston, who has been active in the IEEE Computer Society and in the IEEE Houston Section for many years.
Superconductivity is a very “exotic” behavior observed in certain materials that lose all of their electrical resistance when they are cooled below room temperature to very deep cryogenic temperatures. It was first observed in 1911 by Prof. Heike Kamerlingh Onnes and collaborators at the University of Leiden (The Netherlands) while measuring the resistance of mercury at temperatures just a few degrees above absolute zero (that is, minus 459.7 degrees Fahrenheit). In 2011, the discovery of superconductivity by Onnes and colleagues was designated an IEEE Milestone in Electrical Engineering and Computing and a plaque was dedicated in the building on the University of Leiden campus where the initial experiments had been done. Superconductivity has been observed in more than 10,000 elements, compounds, mixtures and alloys with the highest known transition temperature, to date, of minus 200 degrees Fahrenheit. A comprehensive microscopic theory of superconductivity, which has been quite successful in explaining the behavior of most of the low temperature superconductors, was proposed in 1957 by John Bardeen, Leon Cooper and Robert Schrieffer (the so-called “BCS” theory), for which they received the Nobel Prize in Physics in 1972. A total of five Nobel Prizes in Physics have been awarded to scientists for their research in superconductivity. The status of superconducting materials changed dramatically in 1986 following the work of Mueller and Bednorz (IBM, Switzerland) who reported the discovery of a copper oxide based ceramic material that exhibited superconductivity at a temperature of 35 K. The discovery that Y-123 (the compound yttrium-barium-copper-oxide, with formula Y1Ba2Cu3O7) exhibits superconductivity above the boiling point of liquid nitrogen (77K, or minus 321 Fahrenheit) by a team of researchers. The significance of having superconductivity at temperatures above the boiling point of liquid nitrogen is the drastically reduced cost and complexity of the refrigeration needed to cool the superconductor to temperatures below their superconducting transition temperature. Prior to the discoveries of the Houston group, most of the known superconductors had to be cooled to temperatures near the boiling point of liquid helium (4 kelvin or minus 452 degrees Fahrenheit).
The cost of maintaining an object at or near liquid nitrogen temperatures is at least a factor of 100 smaller than the cost of providing a 4 kelvin environment. This reduction in cost applies for either technique of cryogenic cooling: use of a liquid cryogen (liquid helium for 4 kelvin or liquid nitrogen for 77 kelvin) or use of a closed cycle cryogenic refrigerator (a cryocooler). However, the high temperature superconducting materials tend to be ceramic (and thus very brittle) in nature and very difficult to make into wires and cables for high power applications, or into electronic devices and circuits. As a result, the excitement of reduced cost of operation has to be balanced against the challenges of making useful circuits and systems from these materials. In the last decade, however, great progress has been made in the fabrication of HTS wire, which can now be made in kilometer lengths.
On the morning of November 17, before the actual presentation of the plaque to the University of Houston, a special IEEE Milestone Community Lecture series was held at the Hilton University of Houston Hotel which was open to the general public, including high school students. The series was called “Superconductivity above 77 K in Y-123 – History, Science and Applications,” and was chaired by Dr. John Spargo, Past President of the IEEE Council on Superconductivity. The first speaker in this session was Prof. Paul C. W. Chu, who spoke on “High Temperature Cuprate Superconductor: A History.” He reviewed the status of superconducting materials prior to 1986 when the highest known superconducting transition temperature was 23 kelvin, and the excitement and “near hysteria” following the work of Mueller and Bednorz who, in 1986, reported the discovery of a copper oxide based material which exhibited superconductivity at temperatures as high as 38 K. Chu referred to material from the scientific literature but also showed articles and photographs from the popular national mews media that was caught up in the excitement of “high temperature superconductivity.” He also related the results of the Houston-Alabama group on these materials both at ambient pressure as well as under pressure where transition temperatures as high as 164 kelvin were observed for certain cuprate compounds related to the Y-123 material.
The second speaker in this session was Sir Anthony Leggett, 2003 recipient of the Nobel Prize in Physics, Fellow of the Royal Society (UK) (FRS), and the John D. and Catherine MacArthur Professor and Center for Advanced Study Professor of Physics at the University of Illinois at Urbana-Champaign. Prof. Leggett described the Bardeen-Copper-Schrieffer (BCS) theory of superconductivity, which has been successful to date in explaining the observed behavior of the “low temperature superconductors,” but has not been particularly useful in dealing with the cuprate “high temperature superconductors.” He also reviewed various theoretical approaches being proposed to explain superconductivity at higher temperatures.
The third speaker was Dr. Alan Lauder, Executive Director of the Coalition for the Commercial Applications of Superconductivity (CCAS), the US trade association for superconductivity, and Chairman of the International Superconductivity Industry Summit (ISIS). Dr. Lauder spoke on current and potential applications of superconductors. He also described the challenges facing the commercialization of a new technology, especially one that must be operated at cryogenic temperatures, and the barriers that must be overcome before this technology will be accepted by the commercial marketplace.
| Figure 2. |
Speakers at the special IEEE Milestone Community Lecture series held prior to the IEEE Milestone Dedication Ceremony were Prof. Paul C. W. Chu (left), Sir Anthony Leggett (center) and Dr. Alan Lauder (right).
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Following an IEEE Tribute Luncheon for invited and out-of-town guests at which Prof. Maw-Kuen Wu, a senior team member of the original group and now President of National Dong Hwa University in Taiwan, sent congratulatory greetings via video, the Milestone plaque unveiling ceremony was held at the Hilton University of Houston Hotel. This session was chaired by Mr. Vincent Wedelich, past Chair of the IEEE Houston Section. Following introductory remarks by Mr. Wedelich, there were greetings from the various hosting and sponsoring organizations. Prof Theodore A. Bickard, Chair of the IEEE Region 5 History Committee and Milestones subcommittee, presented a certificate of appreciation from the IEEE History Committee to Prof. Willis King for initiating the proposal for the Milestone, and a letter of appreciation to the IEEE Houston Section for their role in the dedication event. Greetings from the IEEE Region 5 were presented by Mr. T. Scott Atkinson, Chair of the IEEE Region 5 – South Area, and from the IEEE Houston Section by Mr. Anthony Astwood, Chair of the IEEE Power and Energy Society Chapter (IEEE Houston Section). Greetings from the IEEE Council on Superconductivity, which co-hosted the ceremony, were given by its President, Dr. Elie K. Track.
Dr. Track then introduced Professor de Marca, President and CEO of the IEEE, who made the formal presentation of the Plaque designating the University of Houston as the site of an IEEE Milestone for Electrical Engineering and Computing. The plaque was accepted by Dr. Renu Khator, Chancellor of the University of Houston System and President of the University of Houston. During the ceremony, the actual plaque had been placed on a pedestal and covered by a black drape. Once the plaque had been accepted, Prof. Paul C. W. Chu and Dr. Li Gao and Mrs. Ruling Meng, original group members who had been involved in the original discovery and who were able to attend the Ceremony, jointly lifted the drape from the plaque. After brief comments by Prof. Chu, there was a social function with light refreshments.
Following the Dedication Ceremony, the plaque was to be moved to the Science Research Building One on the University of Houston campus where it is permanently mounted in the lobby.
| Figure 3. |
Photograph of the unveiling of the IEEE Milestone plaque at the Hilton University of Houston Hotel by (from left to right) Prof. J. Roberto de Marca, President and CEO of the IEEE; Dr. Renu Khator, Chancellor, University of Houston System, and President, University of Houston; Prof. Allan Jacobson, Director, the Texas Center for Superconductivity at the University of Houston (partially obscured by the drape); Prof. Paul C. W. Chu, Dr. Li Gao and Mrs. Ruling Meng - the latter three being members of the team who worked on the Y-123 materials in 1987.
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November 2014