Microwave spectroscopy of Q1D and Q2D organic conductors

This chapter reviews recent experimental studies of a novel open-orbit magnetic resonance phenomenon. The technique involves measurement of angle-dependent microwave magneto-conductivity and is, thus, closely related to the cyclotron resonance and angle-dependent magnetoresistance techniques. Data for three contrasting materials are presented: (TMTSF)2ClO4, alpha-(BEDT-TTF)2KHg(SCN)4 and kappa-(BEDT-TTF)2I3. These studies reveal important insights into the Fermiology of these novel materials, as well as providing access to important electronic parameters such as the in-plane Fermi velocity and quasiparticle scattering rate. It is argued that all three compounds exhibit coherent three-dimensional band transport at liquid helium temperatures, and that their low-energy magnetoelectrodynamic properties appear to be well explained on the basis of a conventional semiclassical Boltzmann approach. It is also suggested that this technique could be used to probe quasiparticles in nodal superconductors.