Revealing Emergent Magnetic Charge in a Topological Antiferromagnet with Diamond Quantum Magnetometry

Whirling topological textures play a key role in exotic phases of magnetic materials and offer promise for logic and memory applications. In antiferromagnets, these textures exhibit enhanced stability and faster dynamics with respect to ferromagnetic counterparts, but they are also difficult to observe due to their vanishing net magnetic moment. Diamond quantum magnetometry offers a promising route to image such weak features through its high sensitivity and vectorial field detection. Here, we image the topological textures in the archetypal antiferromagnet, hematite, and reveal that these textures host in parallel a rich tapestry of monopolar, dipolar and quadrupolar magnetic charge distributions. By extracting field orientations, we demonstrate direct readout of the previously inaccessible antiferromagnetic vorticity, which is connected to magnetic charge through a duality relation. Our work highlights the critical role that diamond quantum magnetometry could play in exploring emergent phenomena and topological spintronics in quantum materials.

(A.T., H.J., M.H. contributed equally)