Angular Magnetoresistance Measurements as a Probe of the Fermi Surface in Hg1201*

The Fermi surface of underdoped cuprates is reconstructed by charge density wave order. An elucidation of the exact morphology of the reconstructed Fermi-surface is expected to provide insight into the relationship between charge order and superconductivity. We present measurements of the Fermi surface of underdoped HgBa₂CuO_4+d (Hg1201), obtained through angular magnetoresistance. Transport along the c-axis was measured in pulsed magnetic fields of up to 65 T, applied along many polar and azimuthal angles in order to map out the Fermi surface. We discuss the implication of our measurements for the shape of the Fermi surface, including the interlayer warping, and comment on its dependence on temperature and doping.