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Conductance of nano-systems with interactions coupled via conduction electrons: Effect of indirect exchange interactions

Yoichi Asada·Axel Freyn·Jean-Louis Pichard
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Abstract

A nano-system in which electrons interact and in contact with Fermi leads gives rise to an effective one-body scattering which depends on the presence of other scatterers in the attached leads. This non local effect is a pure many-body effect that one neglects when one takes non interacting models for describing quantum transport. This enhances the non-local character of the quantum conductance by exchange interactions of a type similar to the RKKY-interaction between local magnetic moments. A theoretical study of this effect is given assuming the Hartree-Fock approximation for spinless fermions in an infinite chain embedding two scatterers separated by a segment of length L\_c. The fermions interact only inside the two scatterers. The dependence of one scatterer onto the other exhibits oscillations which decay as 1/L\_c and which are suppressed when L\_c exceeds the thermal length L\_T. The Hartree-Fock results are compared with exact numerical results obtained with the embedding method and the DMRG algorithm.

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Yoichi Asada, Axel Freyn, Jean-Louis Pichard. 2006-11-06. Conductance of nano-systems with interactions coupled via conduction electrons: Effect of indirect exchange interactions. https://doi.org/10.1140/epjb%2Fe2006-00352-1

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