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Majorana Fermion Representation For An Antiferromagnetic Spin-1/2 Chain

B. Sriram Shastry·Diptiman Sen
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Abstract

We study the 1-dimensional Heisenberg antiferromagnet with s=1/2 using a Majorana representation of the s=1/2 spins. A simple Hartree-Fock approximation of the resulting model gives a bilinear fermionic description of the model. This description is rotationally invariant and gives power-law correlations in the ``ground state'' in a natural fashion. The excitations are a two-parameter family of particles, which are spin-1 objects. These are contrasted to the ``spinon'' spectrum, and the technical aspects of the representation are discussed, including the problem of redundant states.

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B. Sriram Shastry, Diptiman Sen. 1996-10-18. Majorana Fermion Representation For An Antiferromagnetic Spin-1/2 Chain. https://doi.org/10.1103/physrevb.55.2988

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