| speaker: | Alex C. Hewson
Imperial College, London, UK |
| time: | Tu., 21.08, 14:00-14:50 |
We give a brief introduction and survey of the renormalised perturbation technique, illustrating it with the Anderson impurity model. We show how exact results are generated for the low energy behaviour for this model in an expansion to second order in the renormalised on-site interaction. We show how to calculate the renormalised parameters from an NRG calculation, and how to include an arbitrary magnetic field. Results of calculations for the local spin dynamics of the Anderson model in a magnetic field will be presented and the results compared with direct NRG calculations. Further results will be shown for the infinite dimensional Hubbard model in a magnetic field, and for a quantum dot in a magnetic field with finite bias voltage. We will assess to what class of problems the method might be applied in future work.