  In this study we have measured the magnetoresistance response of inverted
HgTe quantum wells in the presence of a large parallel magnetic field up to 33
T is applied. We show that in quantum wells with inverted band structure a
monotonically decreasing magnetoresistance is observed when a magnetic field up
to order 10 T is applied parallel to the quantum well plane. This feature is
accompanied by a vanishing of non-locality and is consistent with a predicted
modification of the energy spectrum that becomes gapless at a critical in-plane
field $B_{c}$. Magnetic fields in excess of $B_c$ allow us to investigate the
evolution of the magnetoresistance in this field-induced semi-metallic region
beyond the known regime. After an initial saturation phase in the presumably
gapless phase, we observe a strong upturn of the longitudinal resistance. A
small residual Hall signal picked up in non-local measurements suggests that
this feature is likely a bulk phenomenon and caused by the semi-metallicity of
the sample. Theoretical calculations indeed support that the origin of these
features is classical and a power law upturn of the resistance can be expected
due to the specifics of two-carrier transport in thin (semi-)metallic samples
subjected to large magnetic fields.
