title: Change of carrier density at the pseudogap critical point of a cuprate superconductor.
abstract: 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 and its relation to the charge order that reconstructs the Fermi surface at intermediate doping is still unclear. Here we use measurements of the Hall coefficient in magnetic fields up to 88 tesla to show that Fermi-surface 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.
authors.affiliation: Département de physique, Regroupement Québécois sur les Matériaux de Pointe, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Badoux
authors.affiliation: Laboratoire National des Champs Magnétiques Intenses (CNRS, EMFL, INSA, UGA, UPS), Toulouse 31400, France.|AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, 30-059 Krakow, Poland.
authors.forename: W
authors.initials: W
authors.lastname: Tabis
authors.affiliation: Laboratoire National des Champs Magnétiques Intenses (CNRS, EMFL, INSA, UGA, UPS), Toulouse 31400, France.
authors.forename: F
authors.initials: F
authors.lastname: Laliberté
authors.affiliation: Département de physique, Regroupement Québécois sur les Matériaux de Pointe, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Grissonnanche
authors.affiliation: Laboratoire National des Champs Magnétiques Intenses (CNRS, EMFL, INSA, UGA, UPS), Toulouse 31400, France.
authors.forename: B
authors.initials: B
authors.lastname: Vignolle
authors.affiliation: Laboratoire National des Champs Magnétiques Intenses (CNRS, EMFL, INSA, UGA, UPS), Toulouse 31400, France.
authors.forename: D
authors.initials: D
authors.lastname: Vignolles
authors.affiliation: Laboratoire National des Champs Magnétiques Intenses (CNRS, EMFL, INSA, UGA, UPS), Toulouse 31400, France.
authors.forename: J
authors.initials: J
authors.lastname: Béard
authors.affiliation: Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.|Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada.
authors.forename: D A
authors.initials: DA
authors.lastname: Bonn
authors.affiliation: Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.|Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada.
authors.forename: W N
authors.initials: WN
authors.lastname: Hardy
authors.affiliation: Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.|Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Liang
authors.affiliation: Département de physique, Regroupement Québécois sur les Matériaux de Pointe, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada.
authors.forename: N
authors.initials: N
authors.lastname: Doiron-Leyraud
authors.affiliation: Département de physique, Regroupement Québécois sur les Matériaux de Pointe, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada.|Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada.
authors.forename: Louis
authors.initials: L
authors.lastname: Taillefer
authors.affiliation: Laboratoire National des Champs Magnétiques Intenses (CNRS, EMFL, INSA, UGA, UPS), Toulouse 31400, France.|Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada.
authors.forename: Cyril
authors.initials: C
authors.lastname: Proust