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arXiv · 1806.04039

Non-Hermitian Kondo effect in ultracold alkaline-earth atoms

Masaya Nakagawa·Norio Kawakami·Masahito Ueda
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Abstract

We investigate the Kondo effect in an open quantum system, motivated by recent experiments with ultracold alkaline-earth(-like) atoms. Because of inelastic collisions and the associated atom losses, this system is described by a complex-valued Kondo interaction and provides a non-Hermitian extension of the Kondo problem. We show that the non-Hermiticity induces anomalous reversion of renormalization-group flows which violate the $g$-theorem due to non-unitarity and produce a quantum phase transition unique to non-Hermiticity. Furthermore, we exactly solve the non-Hermitian Kondo Hamiltonian using a generalized Bethe ansatz method and find the critical line consistent with the renormalization-group flow.

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Masaya Nakagawa, Norio Kawakami, Masahito Ueda. 2018-06-11. Non-Hermitian Kondo effect in ultracold alkaline-earth atoms. https://doi.org/10.1103/physrevlett.121.203001

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