Spin Dynamics of Individual Magnetic Impurities at the Surface of a Semiconductor

Deposition and embedding at atomically-precise locations of individual magnetic impurities into semiconductor surfaces has been demonstrated with a variety of dopants, including especially transition-metal ions into III-V semiconductors[1]. Predictions[2], experimentally confirmed[3-5] have indicated how the magnetic dopants respond to local strain fields and the surface, but the resulting quenching of the magnetic moment through low symmetry and the spin-orbit interaction has made static measurements of magnetic properties very hallenging[6]. Nevertheless it is possible to predict the expected results for dynamic measurements of magnetic properties and spin dynamics using electrical contacts such as are available using the scanning tunneling microscope. The focus here will be on pairs of magnetic impurities, that interact via the exchange or dipolar interactions[7]. Spin dynamics can be directly viewed through inelastic tunneling spectroscopy, or through low-field magnetoresistance measurements[8,9]. This work was supported by the grant DE-SC0016447, funded by the U. S. Department of Energy, Office of Science.

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