Angle-dependent magnetoresistance of the electron-doped cuprate Pr_2-xCe_xCuO₄

In a previous study on the hole-doped cuprate Nd-LSCO, angle-dependent magnetoresistance (ADMR) measurements revealed two remarkable facts. First, the inelastic scattering rate in the strange metal regime just above the pseudogap critical doping p* has a Planckian value and it is isotropic [1]. Secondly, the Fermi surface of this cuprate undergoes a profound transformation as the doping is reduced below p* [2], confirming directly that a transition to a new metallic normal state has occurred [3,4]. Here we report a similar ADMR study, performed on the electron-doped cuprate Pr_2-xCe_xCuO₄ (PCCO), using special films grown such that the electric current flows along the c-axis. Data up to 42 T were taken at the National High Magnetic Field Laboratory in Tallahassee, on films with dopings ranging from x = 0.14 to x = 0.20, allowing us to access both the strange metal regime of PCCO [4], at x > x* = 0.17, and the metallic state below its quantum critical point, at x < x* = 0.17. We compare both regimes in PCCO to those found in Nd-LSCO.

[1] Grissonnanche et al., Nature 595, 667 (2021).

[2] Fang et al., Nature Physics 18, 558 (2022).

[3] Badoux et al., Nature 531, 210 (2016).

[4] Collignon et al., Physical Review B 95, 224517 (2017).

[5] Legros et al., Nature Physics 15, 142 (2019).