Fermi-surface transformation across the pseudogap critical point of the cuprate superconductor Nd-LSCO

We report high-field measurements of the electrical resistivity and Hall coefficient of the cuprate Nd-LSCO in magnetic fields up to $H = 37.5$~T, large enough to access the normal state at $T = 0$, for closely spaced dopings across the pseudogap critical point at $p^{\star} = 0.235$ [1]. Below $p^{\star}$, both coefficients exhibit an upturn at low temperature, which gets more pronounced with decreasing $p$. Taken together, these upturns show that the normal-state carrier density $n$ at $T = 0$ drops upon entering the pseudogap phase, from $n = 1+p$ above $p^{\star}$ to $n = p$ below. Our data are in quantitative agreement with recent high-field data on YBCO [2] and LSCO [3], showing that a drop in carrier density from $1+p$ to $p$ is a universal signature of the pseudogap transition at $T = 0$.\\ ~[1] C.~Collignon~{\it et al.}, arXiv:1607.05693~(2016).\\ ~[2] S.~Badoux~{\it et al.}, Nature~{\bf 531},~210~(2016).\\ ~[3] F.~Lalibert\’e~{\it et al.}, arXiv:1606.04491~(2016).