Ref HAL: hal-00804167_v1
Ref Arxiv: 1210.7143
DOI: 10.1016/j.nuclphysb.2013.03.001
WoS: 000317450600006
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
41 Citations
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.