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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Spin versus charge noise from Kondo traps

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Dias da Silva, Luis G. G. V. [1] ; de Sousa, Rogerio [2]
Total Authors: 2
[1] Univ Sao Paulo, Inst Fis, BR-05315970 Sao Paulo, SP - Brazil
[2] Univ Victoria, Dept Phys & Astron, Victoria, BC V8W 2Y2 - Canada
Total Affiliations: 2
Document type: Journal article
Source: Physical Review B; v. 92, n. 8 AUG 14 2015.
Web of Science Citations: 4

Magnetic and charge noise have a common microscopic origin in solid-state devices, as described by a universal electron trap model. In spite of this common origin, magnetic (spin) and charge noise spectral densities display remarkably different behaviors when many-particle correlations are taken into account, leading to the emergence of the Kondo effect. We derive exact frequency sum rules for trap noise and perform numerical renormalization-group calculations to show that while spin noise is a universal function of the Kondo temperature, charge noise remains well described by single-particle theory even when the trap is deep in the Kondo regime. We obtain simple analytical expressions for charge and spin noise that account for Kondo screening in all frequency and temperature regimes, enabling the study of the impact of disorder and the emergence of magnetic 1/f noise from Kondo traps. We conclude that the difference between charge and spin noise survives even in the presence of disorder, showing that noise can be more manageable in devices that are sensitive to magnetic (rather than charge) fluctuations and that the signature of the Kondo effect can be observed in spin noise spectroscopy experiments. (AU)

FAPESP's process: 13/50220-7 - Magnetic noise due to Kondo impurities in spintronic devices
Grantee:Luis Gregório Godoy de Vasconcellos Dias da Silva
Support type: Regular Research Grants