Nernst and Seebeck coefficients of the cuprate superconductor YBa2Cu3O6.67: a study of Fermi surface reconstruction.
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.
Chang
J
J
Département de physique & RQMP, Université de Sherbrooke, Sherbrooke, Canada.
Daou
R
R
Proust
Cyril
C
Leboeuf
David
D
Doiron-Leyraud
Nicolas
N
Laliberté
Francis
F
Pingault
B
B
Ramshaw
B J
BJ
Liang
Ruixing
R
Bonn
D A
DA
Hardy
W N
WN
Takagi
H
H
Antunes
A B
AB
Sheikin
I
I
Behnia
K
K
Taillefer
Louis
L