Fermi surface reconstruction in electron-doped cuprates without antiferromagnetic long-range order

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 116; no. 9; pp. 3449 - 3453
• Main Authors: He, Junfeng, Rotundu, Costel R., Scheurer, Mathias S., He, Yu, Hashimoto, Makoto, Xu, Ke-Jun, Wang, Yao, Huang, Edwin W., Jia, Tao, Chen, Sudi, Moritz, Brian, Lu, Donghui, Lee, Young S., Devereaux, Thomas P., Shen, Zhi-xun
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 26.02.2019; National Academy of Sciences, Washington, DC (United States)
• Subjects: angle-resolved photoemission; Antiferromagnetism; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Cuprates; Data points; Doping; Electrons; Energy gap; Fermi surfaces; high-temperature superconductors; Long range order; MATERIALS SCIENCE; Metals; Neutron scattering; Order parameters; Photoelectric emission; Physical Sciences; point; quantum critical; Reconstruction; strongly correlated electrons; topological order; Topology; angle-resolved photoemission; high-temperature superconductors; topological order; strongly correlated electrons; quantum critical point
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1816121116

Fermi surface (FS) topology is a fundamental property of metals and superconductors. In electron-doped cuprate Nd2−x CeₓCuO₄ (NCCO), an unexpected FS reconstruction has been observed in optimal- and overdoped regime (x = 0.15–0.17) by quantum oscillation measurements (QOM). This is all the more puzzling because neutron scattering suggests that the antiferromagnetic (AFM) long-range order, which is believed to reconstruct the FS, vanishes before x = 0.14. To reconcile the conflict, a widely discussed external magnetic-field–induced AFM long-range order in QOM explains the FS reconstruction as an extrinsic property. Here, we report angle-resolved photoemission (ARPES) evidence of FS reconstruction in optimal- and overdoped NCCO. The observed FSs are in quantitative agreement with QOM, suggesting an intrinsic FS reconstruction without field. This reconstructed FS, despite its importance as a basis to understand electron-doped cuprates, cannot be explained under the traditional scheme. Furthermore, the energy gap of the reconstruction decreases rapidly near x = 0.17 like an order parameter, echoing the quantum critical doping in transport. The totality of the data points to a mysterious order between x = 0.14 and 0.17, whose appearance favors the FS reconstruction and disappearance defines the quantum critical doping. A recent topological proposal provides an ansatz for its origin.