Quantum spins on star graphs and the Kondo model - Laboratoire Charles Coulomb (L2C) Accéder directement au contenu
Article Dans Une Revue Nuclear Physics B Année : 2013

Quantum spins on star graphs and the Kondo model

Résumé

We study the XX model for quantum spins on the star graph with three legs (i.e., on a Y-junction). By performing a Jordan-Wigner transformation supplemented by the introduction of an auxiliary space we find a Kondo Hamiltonian of fermions, in the spin 1 representation of su(2), locally coupled with a magnetic impurity. In the continuum limit our model is shown to be equivalent to the 4-channel Kondo model coupling spin-1/2 fermions with a spin-1/2 impurity and exhibiting a non-Fermi liquid behavior. We also show that it is possible to find a XY model such that - after the Jordan-Wigner transformation - one obtains a quadratic fermionic Hamiltonian directly diagonalizable.

Dates et versions

hal-00804167 , version 1 (25-03-2013)

Identifiants

Citer

Nicolas Crampé, Andrea Trombettoni. Quantum spins on star graphs and the Kondo model. Nuclear Physics B, 2013, 871 (3), pp.526. ⟨10.1016/j.nuclphysb.2013.03.001⟩. ⟨hal-00804167⟩
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