Cyclotron resonance studies of electron dynamics in BEDT-TTF salts

Summary form only given. Cyclotron resonance (CR) measurements have been performed on quasi-two dimensional (Q2D) systems of electrons in the BEDT-TTF family of organic charge transfer salts. The use of a resonant cavity in conjunction with various microwave sources of radiation has recently given rise to much more detail than has previously been reported. Structure in the main CR line shape is observed, as well as a series of harmonics. Although the observation of these harmonics may be expected from our experimental geometry, these features do not occur at simple fractions of the fundamental resonance field. It is thought that the strong correlation between carriers in these materials leads to a distortion of the energy band close to the Fermi edge. A simple model of the renormalised Landau levels suggests that the field position of the CR harmonics may be much more influenced by the electron-electron interactions than is the fundamental CR. An extensive study of the energy and temperature dependence of the CR has been used to test the validity of the model and to assess whether the CR harmonics may provide us with a greater. understanding of the types of interaction giving rise to the novel ground state properties in this class of material.