Change of carrier density at the pseudogap critical point of a cuprate superconductor

Article

关键词: FERMI-SURFACE;    QUANTUM OSCILLATIONS;    SINGLE-CRYSTALS;    STATE;    DEPENDENCE;    SCATTERING;    ORDER;    TL2BA2CUO6+DELTA;    TRANSPORT;    EVOLUTION;   

DOI  :  10.1038/nature16983

来源: SCIE

【 摘 要 】

The pseudogap is a partial gap in the electronic density of states that opens in the normal (non-superconducting) state of cuprate superconductors and whose origin is a long-standing puzzle. Its connection to the Mott insulator phase at low doping (hole concentration, p) remains ambiguous(1) and its relation to the charge order(2-4) that reconstructs the Fermi surface(5,6) at intermediate doping is still unclear(7-10). Here we use measurements of the Hall coefficient in magnetic fields up to 88 tesla to show that Fermisurface reconstruction by charge order in the cuprate YBa2Cu3Oy ends sharply at a critical doping p = 0.16 that is distinctly lower than the pseudogap critical point p* = 0.19 (ref. 11). This shows that the pseudogap and charge order are separate phenomena. We find that the change in carrier density n from n = 1 + p in the conventional metal at high doping (ref. 12) to n = p at low doping (ref. 13) starts at the pseudogap critical point. This shows that the pseudogap and the antiferromagnetic Mott insulator are linked.

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