|Critical excitation spectrum of a quantum chain with a local 3 Ising spin coupling|
|Tuesday 23 March 2010 , 11h25|
|Salle de séminaire du groupe de Physique Statistique|
We use the phenomenological renormalization group to measure energies and discrete momenta of the low-lying excitations at a critical line of a quantum spin chain having local couplings between 3 Ising spins. The measured spectra agrees with the excitation spectrum predicted by the ($D_4$, $A_4$) minimal conformal field theory under a nontrivial correspondence between lattice momenta and momenta at the critical line.