title: Nernst and Seebeck coefficients of the cuprate superconductor YBa2Cu3O6.67: a study of Fermi surface reconstruction.
abstract: The Seebeck and Nernst coefficients S and nu of the cuprate superconductor YBa{2}Cu{3}O{y} (YBCO) were measured in a single crystal with doping p=0.12 in magnetic fields up to H=28 T. Down to T=9 K, nu becomes independent of field by H approximately 30 T, showing that superconducting fluctuations have become negligible. In this field-induced normal state, S/T and nu/T are both large and negative in the T-->0 limit, with the magnitude and sign of S/T consistent with the small electronlike Fermi surface pocket detected previously by quantum oscillations and the Hall effect. The change of sign in S(T) at T approximately 50 K is remarkably similar to that observed in La2-xBaxCuO4, La{2-x-y}Nd{y}Sr_{x}CuO{4}, and La{2-x-y}Eu{y}Sr{x}CuO{4}, where it is clearly associated with the onset of stripe order. We propose that a similar density-wave mechanism causes the Fermi surface reconstruction in YBCO.
authors.affiliation: Département de physique & RQMP, Université de Sherbrooke, Sherbrooke, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Chang
authors.forename: R
authors.initials: R
authors.lastname: Daou
authors.forename: Cyril
authors.initials: C
authors.lastname: Proust
authors.forename: David
authors.initials: D
authors.lastname: Leboeuf
authors.forename: Nicolas
authors.initials: N
authors.lastname: Doiron-Leyraud
authors.forename: Francis
authors.initials: F
authors.lastname: Laliberté
authors.forename: B
authors.initials: B
authors.lastname: Pingault
authors.forename: B J
authors.initials: BJ
authors.lastname: Ramshaw
authors.forename: Ruixing
authors.initials: R
authors.lastname: Liang
authors.forename: D A
authors.initials: DA
authors.lastname: Bonn
authors.forename: W N
authors.initials: WN
authors.lastname: Hardy
authors.forename: H
authors.initials: H
authors.lastname: Takagi
authors.forename: A B
authors.initials: AB
authors.lastname: Antunes
authors.forename: I
authors.initials: I
authors.lastname: Sheikin
authors.forename: K
authors.initials: K
authors.lastname: Behnia
authors.forename: Louis
authors.initials: L
authors.lastname: Taillefer