Seminarium Fizyki Materii Skondensowanej

Recently non-analytic dependences of thermodynamic parameters of Fermiliquids have attracted much attention. In this talk I will discuss thesenon-analyticities which arise due to long range interactions betweenquasi-particles. In particular I will show that, in a weak externalmagnetic field, certain quasi-particle properties exhibit a non-analyticdependence on the magnetic field. The corresponding prefactors will becalculated to leading order in the interaction and it will be shown thatthey are determined fully by low-energy scattering processes. Finally Iwill discuss how the non-analytic terms can be detected in experiments.