T-linear resistivity and Planckian dissipation in cuprates

The perfectly linear temperature dependence of the resistivity observed as T→0 in a variety of metals close to a quantum critical point is a major puzzle of condensed matter physics. I will present high-field magneto-transport measurements of two hole-doped cuprates, near their pseudogap critical point p*, supporting that T-linear resistivity as T→0 is a generic property of cuprates, associated with a universal scattering rate. We measured the low-T resistivity of the bilayer cuprate Bi2212 just above p* [1] and found that it exhibits a T-linear dependence with the same slope as in the single-layer cuprate Nd-LSCO close to its own p* and in the low-T limit, despite their very different Fermi surfaces and structural, superconducting and magnetic properties. We also observed, using the Drude formula, that in various cuprates showing this low-T phenomenon (hole-doped and electron-doped) the slope of this T-linear resistivity is given by a universal relation implying a specific scattering rate for charge carriers: 1τ= αh/2πk_B T, where h is Planck’s constant, k B is the Boltzmann constant and α a constant of order unity. This specific scattering rate corresponds to what is called the Planckian limit [2], and has been attributed to other metals showing a T-linear resistivity [3]. Finally, we directly measured the scattering rate in the single-layer cuprate Nd- LSCO, just above p* and in the low-T limit, using angle-dependent magneto-resistance measurements [4]: these experiments reveal an inelastic scattering rate which is isotropic and linear in temperature, and whose magnitude is consistent with Planckian dissipation.

[1] Legros et al., Nat. Phys. 15, 142 (2019)
[2] Zaanen, SciPost Phys. 6, 061 (2019)
[3] Bruin et al., Science 339, 809 (2013)
[4] Grissonnanche et al., arXiv:2011.13054 (2020)