  It has long been recognized that the key to unlocking the mystery of cuprate
high-Tc superconductivity lies in understanding the anomalous normal state from
which pairs form and condense. While many of its defining properties have been
identified, they are often considered either at a singular doping level or as
an isolated phenomenon as a function of doping. As a result, their relation to
each other and to the pseudogap (PG), strange metal (SM) and
non-superconducting (non-SC) regimes that define the cuprate phase diagram has
yet to be elucidated. Here, we report a high-field in-plane MR study on several
cuprate families spanning all 3 regimes that reveal a complex yet nonetheless
systematic evolution of the form of the MR, with each regime possessing its own
distinct scaling behavior. In the PG regime, the MR exhibits pure H/T^2 scaling
at low fields and H-linearity at the highest field strengths. While the
H-linearity persists inside the SM regime, the scaling changes abruptly to H/T.
The size of the H-linear slope, meanwhile, is found to be correlated with both
the T-linear resistivity coefficient and Tc, strengthening the characterization
of the SM regime as a quantum critical phase. We interpret the omnipresence of
H-linear MR across both regimes as a signature of highly anisotropic, possibly
discontinuous features on the Fermi surface. Finally, within the non-SC,
Fermi-liquid regime, we observe a recovery of conventional Kohler scaling. This
comprehensive study establishes the distinct nature of the magnetotransport
within each regime and identifies power-law scaling of the normal state MR as a
defining feature of SC hole-doped cuprates. The incompatibility of such
power-law scaling with any known variant of Boltzmann transport theory
motivates the quest for an altogether new theoretical framework, one in which
the MR is entirely decoupled from elastic impurity scattering.
