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Magnon Wave-function and Impurity Effects in S=1 Antiferromagnetic Chains: A Large-n Approach

Alistair Savage·Ian Affleck
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Abstract

A large-n approximation to the S=1 antiferromagnetic chain, using the symmetric tensor representation and its conjugate, is developed to order 1/n in order to calculate the magnon wave-function and to study the effect of modifying the exchange coupling from J to J' on a single link. It is shown that a magnon boundstate exists below the Haldane gap for arbitrarily small negative J'-J but only above a certain critical value of J'-J for positive values. In the former case the binding energy vanishes as the square of (J-J').

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Alistair Savage, Ian Affleck. 1998-08-31. Magnon Wave-function and Impurity Effects in S=1 Antiferromagnetic Chains: A Large-n Approach. https://doi.org/10.1103/physrevb.59.3635

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