High $Tc$ May Not Need Phonons; Supercurrents Increase Available to Purchase

Were any surprising and unexpected new results presented at the special panel discussion on new high‐temperature superconductors, a reporter asked at the first of the two press conferences AIP organized on the morning after the historic, all‐night panel discussion on 18 March at the APS meeting in New York. Among interesting new results, physicists at the press conference concurred, were evidence for a transition to an antiferromagnetic state in lanthanum‐copper oxide, anomalies at 120 K in the resistivity of some oxides similar to those that become superconducting between 90 K and 95 K, suggesting that it might be possible to achieve superconductivity at even higher temperatures, and fabrication of wires containing the recently discovered superconducting material lanthanum‐strontium‐copper oxide, with a better current‐carrying capacity in the superconducting state. The first of these results, they hoped, could provide the key to understanding why these oxides remain superconducting at temperatures up to 90 K; the last could open the door to useful applications of these materials. (See PHYSICS TODAY, April, page 17.)