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Impurity-induced moments in underdoped cuprates

G. Khaliullin·R. Kilian·S. Krivenko·P. Fulde
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Abstract

We examine the effect of a nonmagnetic impurity in a two-dimensional spin liquid in the spin-gap phase, employing a drone-fermion representation of spin-1/2 operators. The properties of the local moment induced in the vicinity of the impurity are investigated and an expression for the nuclear-magnetic- resonance Knight shift is derived, which we compare with experimental results. Introducing a second impurity into the spin liquid an antiferromagnetic interaction between the moments is found when the two impurities are located on different sublattices. The presence of many impurities leads to a screening of this interaction as is shown by means of a coherent-potential approximation. Further, the Kondo screening of an impurity-induced local spin by charge carriers is discussed.

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G. Khaliullin, R. Kilian, S. Krivenko, P. Fulde. 1997-09-10. Impurity-induced moments in underdoped cuprates. https://doi.org/10.1103/physrevb.56.11882

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