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The underscreened Kondo effect in ladder systems

Karyn Le Hur
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Abstract

We introduce a new Kondo ladder model by coupling the well-known Takhtajan-Babujan S=1 chain to a half-filled one-dimensional electron gas, and we solve it using quantum field theory techniques. Through the so-called underscreened Kondo effect, this gives novel insights into low-dimensional spin liquid systems. For instance, the optical conductivity reveals only a pseudogap at $k=π$ despite of the insulating state, a coherent magnon peak in the dynamical spin susceptibility coexists with an incoherent spinon background, the magnetization yields a fractional-like quantization. More generally, this problem belongs to the class of Luttinger liquids in active environments, a topic of importance not only to the Kondo physics, but also to striped phases or carbon nanotubes. Experimental consequences on heavy-fermion systems are also discussed.

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Karyn Le Hur. 1999-06-23. The underscreened Kondo effect in ladder systems. https://doi.org/10.1103/physrevlett.83.848

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