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arXiv · 1504.05421

Multiple magnetic impurities on surfaces: Scattering and quasiparticle interference

Andrew K. Mitchell·Philip G. Derry·David E. Logan
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Abstract

We study systems of multiple interacting quantum impurities deposited on a metallic surface in a 3D host. For the real-space two-impurity problem, using numerical renormalization group calculations, a rich range of behavior is shown to arise due to the interplay between Kondo physics and effective RKKY interactions - provided the impurity separation is small. Such calculations allow identification of the minimum impurity separation required for a description in terms of independent impurities, and thereby the onset of the 'dilute impurity limit' in many-impurity systems. A 'dilute cluster' limit is also identified in systems with higher impurity density, where inter-impurity interactions are only important within independent clusters. We calculate the quasiparticle interference (QPI) due to two and many impurities, and explore the consequences of the independent impurity/cluster paradigms. Our results provide a framework to investigate the effects of disorder due to interacting impurities at experimentally relevant surface coverages.

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Andrew K. Mitchell, Philip G. Derry, David E. Logan. 2015-06-15. Multiple magnetic impurities on surfaces: Scattering and quasiparticle interference. https://doi.org/10.1103/physrevb.91.235127

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