Coherent terahertz spectroscopy of the vortex-state of cuprate superconductors

We review the progress towards an understanding of the electrodynamics in the vortex-state which arises in response to a magnetic field. B. Experimentally, the goal is to characterize the conductivity of cuprate superconductors in the presence of an applied magnetic field over a broad frequency range from microwave to infrared wavelengths. The theoretical challenge is to understand these measurements with microscopic, as well as phenomenological, models. In describing the experiments to date we will focus on a relatively new technique, coherent terahertz spectroscopy, which is uniquely capable of measuring the complete complex conductivity tensor.