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Kondo effect in a quantum critical ferromagnet

Yupeng Wang·Jianhui Dai
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Abstract

We study the Heisenberg ferromagnetic spin chain coupled with a boundary impurity. Via Bethe ansatz solution, it is found that (i) for J>0, the impurity spin behaves as a diamagnetic center and is completely screened by 2S bulk spins in the ground state, no matter how large the impurity spin is; (ii) The specific heat of the local composite (impurity plus 2S bulk spins which form bound state with it) shows a simple power law $C_{loc}\sim T^{3/2}$. (iii)For J<0, the impurity is locked into the critical behavior of the bulk. Possible phenomena in higher dimensions are discussed.

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Yupeng Wang, Jianhui Dai. 1999-03-10. Kondo effect in a quantum critical ferromagnet. https://doi.org/10.1103/physrevb.59.13561

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