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arXiv · 1211.3406

Dimensionality effects in the LDOS of ferromagnetic hosts probed via STM: spin-polarized quantum beats and spin filtering

A. C. Seridonio·S. C. Leandro·L. H. Guessi·E. C. Siqueira·F. M. Souza·E. Vernek·M. S. Figueira·J. C. Egues
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Abstract

We theoretically investigate the local density of states (LDOS) probed by a STM tip of ferromagnetic metals hosting a single adatom and a subsurface impurity. We model the system via the two-impurity Anderson Hamiltonian. By using the equation of motion with the relevant Green functions, we derive analytical expressions for the LDOS of two host types: a surface and a quantum wire. The LDOS reveals Friedel-like oscillations and Fano interference as a function of the STM tip position. These oscillations strongly depend on the host dimension. Interestingly, we find that the spin-dependent Fermi wave numbers of the hosts give rise to spin-polarized quantum beats in the LDOS. While the LDOS for the metallic surface shows a damped beating pattern, it exhibits an opposite behavior in the quantum wire. Due to this absence of damping, the wire operates as a spatially resolved spin filter with a high efficiency.

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A. C. Seridonio, S. C. Leandro, L. H. Guessi, E. C. Siqueira, F. M. Souza, E. Vernek, M. S. Figueira, J. C. Egues. 2013-01-03. Dimensionality effects in the LDOS of ferromagnetic hosts probed via STM: spin-polarized quantum beats and spin filtering. https://doi.org/10.1103/physrevb.87.125104

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