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Persistent currents through a quantum impurity: Protection through integrability

Johan Nilsson·H. -P. Eckle·Henrik Johannesson
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Abstract

We consider an integrable model of a one-dimensional mesoscopic ring with the conduction electrons coupled by a spin exchange to a magnetic impurity. A symmetry analysis based on a Bethe Ansatz solution of the model reveals that the current is insensitive to the presence of the impurity. We argue that this is true for any integrable impurity-electron interaction, independent of choice of physical parameters or couplings. We propose a simple physical picture of how the persistent current gets protected by integrability.

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Johan Nilsson, H. -P. Eckle, Henrik Johannesson. 2007-09-17. Persistent currents through a quantum impurity: Protection through integrability. https://doi.org/10.1103/physrevb.76.073408

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