Thermoelectric response near a quantum critical point: The case of CeCoIn5

We present a study of thermoelectric coefficients in CeCoIn5 down to 0.1K and up to 16T in order to probe the thermoelectric signatures of quantum criticality. In the vicinity of the field-induced quantum critical point, the Nernst coefficient ν exhibits a dramatic enhancement without saturation down to the lowest measured temperature. The dimensionless ratio of the Seebeck coefficient to the electronic specific heat shows a minimum at a temperature close to threshold of the quasiparticle formation. Close to Tc(H), in the vortex-liquid state, the Nernst coefficient behaves anomalously in puzzling contrast with other superconductors and standard vortex dynamics.