Fermi-surface pockets in magnetic underdoped cuprates from first principles

Using an innovative first-principles band theory enabling the exploration of Mott-insulating magnetic cuprates, we study the Fermi surface of underdoped Y$_{1-x}$CaxBa2Cu3O6 in a selection of magnetically ordered and polaronic states. Inclusion of doping on the antiferromagnetically ordered CuO2 planes causes the appearance of small, hole-like Fermi-surface pockets centered around the nodal points. The pocket properties (area, mass) depend on the underlying magnetic ordering (e.g. change with polaron formation), although the hole-like character is rather persistent for all the examined magnetic states