Critical dynamic response of the dilute antiferromagnetic chain
Résumé
The transverse dynamic response of the dilute classical Heisenberg antiferromagnetic chain is calculated near the percolation threshold as k to 0 and k to pi . In the critical limit the universal dynamic structure function, which is calculated in closed form, exhibits dynamic scaling with exponents z=1, eta T=1. This function displays the crossover from spin wave (k- pi ) xi p>>1 to hydrodynamic (k- pi ) xi p<<1 response. The relevance of the results to the experimental situation is discussed.