Detecting and Quantifying Surface Atomic-Layer Magnetism via X-ray-Excited Tunneling
ORAL
Abstract
We report the detection of surface atomic-layer magnetism in Ni/Cu(111) films using X-ray-excited tunneling (XET) implemented in synchrotron X-ray scanning tunneling microscopy (SX-STM). Circularly polarized X-rays incident on Ni/Cu(111) heterostructures generate a tunneling current that carries local X-ray magnetic circular dichroism (XMCD) contrast. By simultaneously recording tunneling and total-electron-yield signals, we directly compare surface-sensitive and bulk-averaged magnetism, revealing enhanced magnetic moments confined to the topmost atomic layer, consistent with previous theoretical predictions of surface-moment enhancement. Density-functional calculations provide electronic-structure and charge-transfer context. This work establishes XET as a powerful probe of element-specific surface magnetism, bridging tunneling detection with synchrotron X-ray spectroscopy.
*We acknowledge financial support from the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Science and Engineering Division. Work performed at the Center for Nanoscale Materials and Advanced Photon Source, both U.S. Department of Energy Office of Science User Facilities, was supported by the U.S. DOE, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357
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Publication: A manuscript based on these results has been completed and is being prepared for submission to a peer-reviewed journal.
Presenters
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Sineth M Premarathna
- Ohio University