Imaging the magnetic configuration of thin films has been a long-standing area of research. The emergence of two-dimensional ferromagnetic materials in the last few years calls for innovation in the field of magnetic imaging. As the magnetic moments are extremely small, standard techniques like superconducting quantum interference devices, torque magnetometry, magnetic force microscopy, and Kerr effect microscopy are challenging and often lead to the detection of parasitic magnetic contributions or spurious effects. In this work, we report a magnetic microscopy technique based on the combination of magnetic circular dichroism and the Seebeck effect in a ferromagnet-semiconductor bilayer. We implement this method with perpendicularly magnetized $\mathrm{Co}$/$\mathrm{Pt}$ multilayers sputtered on $\mathrm{Ge}$(111). We further show that the electrical detection of magnetic circular dichroism is more sensitive than the Kerr magnetometry, especially in the ultrathin film regime, which makes it particularly promising for the study of emergent two-dimensional ferromagnetic materials.

• Received 8 September 2020
• Revised 30 October 2020
• Accepted 7 December 2020

DOI:https://doi.org/10.1103/PhysRevApplied.15.014002