Fermi surface transformation across the pseudogap critical point in the cuprate Nd-LSCO from thermoelectric measurements

ORAL

Abstract

In cuprate superconductors, the nature of the pseudogap phase and its interplay with superconductivity are still unclear. Its onset at a doping p* is characterized by a drop in carrier density n from n=1+p above p* to n=p below p* [1]. In Nd0.4La1.6-xSrxCuO4 (Nd-LSCO), this shows up as a low-temperature upturn in the resistivity ρ and Hall coefficient RH at dopings below p*=0.23 [2]. Here we present thermoelectric measurements in Nd-LSCO across p*, in magnetic fields large enough to suppress superconductivity. For a heat current in the CuO2 planes, the Seebeck coefficient S shows a large increase at low temperature below p*, confirming the loss of carrier density. Alon the c-axis, we find that S is isotropic for p > p*, i.e. Sc/T and Sa/T are equal (and positive) in the T=0 limit. In sharp contrast, Sc becomes negative at low temperature when p < p*, revealing a profound change in the Fermi surface topology across p*. Using a Boltzmann transport model, which is shown to calculate accurately resistivity with a k-dependent scattering rate [3], we find that one needs an energy dependent scattering to get the correct sign and temperature dependence of Sa and Sc.
[1] Badoux et al, Nature 531, 210 (2016)
[2] Collignon et al, PRB 95, 224517 (2017)
[3] Fang et al, arXiv:2004.01725

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Presenters

  • Adrien Gourgout

    • Institut Quantique, Département de physique & RQMP, Université de Sherbrooke
    • Universite de Sherbrooke (Canada)
    • Universite de Sherbrooke

Authors

  • Adrien Gourgout

    • Institut Quantique, Département de physique & RQMP, Université de Sherbrooke
    • Universite de Sherbrooke (Canada)
    • Universite de Sherbrooke

  • Gael Grissonnanche

    • Institut Quantique, Département de physique & RQMP, Université de Sherbrooke
    • Universite de Sherbrooke (Canada)
    • Universite de Sherbrooke
    • Cornell University

  • Clement Collignon

    • Universite de Sherbrooke
    • Physics, Massachusetts Institute of Technology
    • Université de Sherbrooke

  • Sven Badoux

    • Institut Quantique, Département de physique & RQMP, Université de Sherbrooke
    • Universite de Sherbrooke

  • Amirreza Ataei

    • Institut Quantique, Département de physique & RQMP, Université de Sherbrooke
    • Universite de Sherbrooke (Canada)
    • Universite de Sherbrooke
    • Université de Sherbrooke

  • Francis Laliberte

    • Institut Quantique, Département de physique & RQMP, Université de Sherbrooke
    • Universite de Sherbrooke (Canada)
    • Universite de Sherbrooke
    • Université de Sherbrooke

  • Simon Verret

    • Universite de Sherbrooke
    • Physics and Institut quantique, Université de Sherbrooke
    • Université de Sherbrooke

  • Jianshi Zhou

    • University of Texas at Austin
    • Materials Science and Engineering Program, Department of Mechanical Engineering, University of Texas at Austin
    • University of Texas (Austin, USA)
    • University of Texas
    • Texas Materials Institute, University of Texas at Austin
    • Materials Science and Engineering Program, Mechanical Engineering, University of Texas at Austin

  • Nicolas Doiron-Leyraud

    • Institut Quantique, Département de physique & RQMP, Université de Sherbrooke
    • Universite de Sherbrooke

  • Louis Taillefer

    • Institut Quantique, Département de physique & RQMP, Université de Sherbrooke
    • Universite de Sherbrooke (Canada)
    • Universite de Sherbrooke
    • Université de Sherbrooke