Magnetotransport signatures of antiferromagnetism coexisting with charge order in the trilayer cuprate HgBaCaCuO.

Multilayered cuprates possess not only the highest superconducting temperature transition but also offer a unique platform to study disorder-free CuO planes and the interplay between competing orders with superconductivity. Here, we study the underdoped trilayer cuprate HgBaCaCuO and we report quantum oscillation and Hall effect measurements in magnetic field up to 88 T. A careful analysis of the complex spectra of quantum oscillations strongly supports the coexistence of an antiferromagnetic order in the inner plane and a charge order in the outer planes. The presence of an ordered antiferromagnetic metallic state that extends deep in the superconducting phase is a key ingredient that supports magnetically mediated pairing interaction in cuprates.