Shubnikov-de Haas Quantum Oscillations Reveal a Reconstructed Fermi Surface Near Optimal Doping in a Thin Film of the Cuprate Superconductor Pr1.86Ce0.14CuO4±δ

Yoshiharu Krockenberger¹, Ai Ikeda¹, Hiroshi Irie², Hideki Yamamoto¹,
Nicholas P. Breznay³, Ian M. Hayes³, Ross McDonald⁴, and James G. Analytis³
¹Materials Science Laboratory, ²Physical Science Laboratory,
³University of California, Berkeley, ⁴NHMFL, Los Alamos National Laboratory

　Understanding the ordering phenomena that compete or coexist with superconductivity in the cuprate superconductors remains an outstanding challenge. Central to this effort is the identification of Fermi surface topology and evolution with doping via studies of magnetic quantum oscillations (QO), led by initial observations of QO in hole-doped YBa₂Cu₃O_6.5[1]. We reported [2] on the Fermi surface topology and effective mass in the electron-doped cuprate superconductor Pr_2–xCe_xCuO₄ (PCCO) with x = 0.14. PCCO thin films have been grown by molecular beam epitaxy onto (001) SrTiO₃ substrates and annealed in order to maximize the mean-free path length [3]. We observe Shubnikov-de Haas QO in a PCCO thin film measured under extreme magnetic fields up to 92 T, where magneto-transport data [Fig. 1(A)] show evidence for a small Fermi surface pocket (255 T), a light quasi-particle with effective mass of m^* = 0.43 m_e, allowing direct determination of the orbitally averaged Fermi velocity of v_F = 2.4×10⁵ m/s. For comparison, the Hall conductivity at 2 K is 0.9×10^–9 Ωm/T, resulting in a charge carrier density per CuO₂ plane of 0.66 by assuming a single parabolic band [Fig. 1(B)]. The small Fermi surface pocket indicates a reconstruction [Fig. 1(C)], coupled with a similar observation of Ce-free Pr₂CuO₄ films [4], suggests that small Fermi surface pockets are a universal feature of cuprate superconductors with square-planar coordinated copper.