Ferromagnetic order beyond the superconducting dome in a cuprate superconductor

• Published in: Science (American Association for the Advancement of Science) Vol. 368; no. 6490; pp. 532 - 534
• Main Authors: Sarkar, Tarapada, Wei, D S, Zhang, J, Poniatowski, N R, Mandal, P R, Kapitulnik, A, Greene, Richard L
• Format: Journal Article
• Language: English
• Published: United States The American Association for the Advancement of Science 01-05-2020; American Association for the Advancement of Science (AAAS)
• Subjects: Antiferromagnetism; Charge density waves; Cuprates; Domes; Doping; Fermi liquids; Ferromagnetic materials; High temperature superconductors; Hysteresis; Liquid metals; Magnetism; Magnetoresistance; Magnetoresistivity; Metals; Optical properties; Phase diagrams; Signatures; Superconductivity; Thin films
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.aax1581

According to conventional wisdom, the extraordinary properties of the cuprate high-temperature superconductors arise from doping a strongly correlated antiferromagnetic insulator. The highly overdoped cuprates-whose doping lies beyond the dome of superconductivity-are considered to be conventional Fermi liquid metals. We report the emergence of itinerant ferromagnetic order below 4 kelvin for doping beyond the superconducting dome in thin films of electron-doped La
Ce
CuO
(LCCO). The existence of this ferromagnetic order is evidenced by negative, anisotropic, and hysteretic magnetoresistance, hysteretic magnetization, and the polar Kerr effect, all of which are standard signatures of itinerant ferromagnetism in metals. This surprising result suggests that the overdoped cuprates are strongly influenced by electron correlations.