Evidence for Superconductivity above 260 K in Lanthanum Superhydride at Megabar Pressures

Recent predictions and experimental observations of high T_{c} superconductivity in hydrogen-rich materials at very high pressures are driving the search for superconductivity in the vicinity of room temperature. We have developed a novel preparation technique that is optimally suited for megabar pressure syntheses of superhydrides using modulated laser heating while maintaining the integrity of sample-probe contacts for electrical transport measurements to 200 GPa. We detail the synthesis and characterization of lanthanum superhydride samples, including four-probe electrical transport measurements that display significant drops in resistivity on cooling up to 260 K and 180-200 GPa, and resistivity transitions…

• NS
  National Science Foundation

  Awards: DE-FG02-99ER45775, DMR-1809783, DE-NA0001974, DE-NA-0002006, DE-AC02-06CH11357, 1809783
• UD
  U.S. Department of Energy

  Awards: AC02-06CH11357, FG02-99ER45775, DE-SC0001057, DE-AC02, DE-NA0001974, 06CH11357, DE-FG02-, DE-AC02-06CH11357, DE-FG02-99ER45775, DE-NA-0002006, DE-FG02, DE-AC02-
• OO
  Office of Science

  Awards: DE-AC02-06CH11357, DE-NA0001974, DE-AC02, 06CH11357, DE-FG02-99ER45775, DE-SC0001057, AC02-06CH11357
• NN
  National Nuclear Security Administration

  Awards: 0002006, DE-AC02-06CH11357, DE-NA-0002006, DE-NA0001974
• DO
  Division of Materials Research

  Awards: DE-AC02-06CH11357, DE-FG02-99ER45775
• BE
  Basic Energy Sciences

  Awards: DE-AC02, DE-FG02, AC02-06CH11357, DE-NA0001974, 06CH11357, DE-SC0001057
• AN
  Argonne National Laboratory

  Awards: DE-AC02, 06CH11357, AC02-06CH11357, DE-NA0001974, DE-FG02-99ER45775