Cornell physicists have discovered that minimizing disorder, not varying electron count, is the key factor for controlling the superconductivity in the unique material iron selenide (FeSe), a new insight for understanding high-temperature superconductors.\u00a0<\/p>\n
Using a new technique to control this iron-based superconductor, researchers in Kyle Shen\u2019s lab<\/a> have found that iron selenide\u2019s superconducting \u201cdome\u201d \u2013\u00a0the curve tracing how the superconductivity strengthens and then weakens as the properties are tuned \u2013 is more closely linked to resistance caused by imperfections in its crystal lattice rather than the number of electrons flowing through the crystal. Iron selenide could be fundamentally different than other high-temperature (or unconventional) superconductors, the finding suggests.\u00a0<\/p>\n \u201cWe found that in this material, that dome is driven by factors much different than what you see normally,\u201d said postdoctoral researcher Paul Malinowski, a former Klarman Postdoctoral Fellow in the College of Arts and Sciences (A&S). \u201cIt\u2019s not driven by how many electrons you\u2019re adding in, but rather, it\u2019s driven by the obstacles the electrons are hitting \u2013\u00a0how perfect or imperfect is the crystal lattice?\u201d\u00a0<\/p>\n The study \u201cWhat Controls the Superconducting Dome of Electron-doped FeSe<\/a>?\u201d published in Proceedings of the National Academy of Sciences Aug. 20 with Malinowski as first author. \u201cIt\u2019s an important new result that could give a lot of insight into high-temperature superconductivity,\u201d said Shen<\/a>, the James A. Weeks Professor of Physical Sciences and Stephen H. Weiss Presidential Fellow (A&S) and director of the Laboratory of Atomic and Solid State Physics, corresponding author of the study.\u00a0<\/p>\n