• Hayden, S. M.
• Lester, C.
• Afshar, S. A. A.
• Croft, T. P.
• Doiron-Leyraud, N.
• Yamada, K.
• Takagi, H.
• Fortier, S.
• Leboeuf, D.
• Ouellet, A.
• Graf, D.
• Badoux, S.
• Taillefer, Louis

Abstract

The Seebeck coefficient S of the cuprate superconductor La_2-xSr_xCuO₄ (LSCO) was measured in magnetic fields large enough to access the normal state at low temperatures, for a range of Sr concentrations from x = 0.07 to x = 0.15. For x = 0.11, 0.12, 0.125, and 0.13, S/T decreases upon cooling to become negative at low temperatures. The same behavior is observed in the Hall coefficient R_H(T). In analogy with other hole-doped cuprates at similar hole concentrations p, the negative S and R_H show that the Fermi surface of LSCO undergoes a reconstruction caused by the onset of charge-density-wave modulations. Such modulations have indeed been detected in LSCO by x-ray diffraction in precisely the same doping range. Our data show that in LSCO this Fermi-surface reconstruction is confined to 0.085 < p < 0.15. We argue that in the field-induced normal state of LSCO, charge-density-wave order ends at a critical doping p_CDW = 0.15 ± 0.005, well below the pseudogap critical doping p* ≃ 0.19.

Topics

• density
• impedance spectroscopy
• surface
• x-ray diffraction