Linear-in-field magnetoresistance in cuprates

The normal state of cuprate superconductors near the pseudogap critical point p* has been investigated by various measurements in high magnetic fields [1]. Resistivity shows a T-linear regime near p* whose magnitude appears to be controlled by a scattering rate in the Planckian limit [2].

A T-linear resistivity is observed, for example, in Nd-LSCO at a doping p = 0.24 (p* = 0.23) [3] and in LSCO at p = 0.19 (p* ≈ 0.18) [4]. In the latter material, a linear-in-field dependence of the resistivity is also reported, whose relation to the Planckian dissipation remains to be understood.

Here we report measurements of the resistivity in Nd-LSCO and LSCO near p* in magnetic fields H up to 85 T. The magnetoresistance (MR) is found to evolve from H-linear at low T to H-quadratic at high T, much as reported for LSCO at p = 0.19 [4]. We investigate this behaviour with calculations based on the Fermi surface geometry and scattering rate anisotropy deduced from a study of angle-dependent magnetoresistance (ADMR) in Nd-LSCO at p = 0.24 [5]. We also explore the MR of Nd-LSCO at p < p*.

[1] Proust & Taillefer, ARCMP.10,409 (2019)
[2] Legros et al., Nat. Phys.15,142 (2019)
[3] Daou et al., Nat. Phys.5,31 (2019)
[4] Giraldo-Gallo et al., Science 361,479 (2018)
[5] Fang et al., arXiv:2004.01725 (2020)