Microwave conductivity and penetration depth in the heavy fermion superconductor CeCoIn₅

The electrodynamic properties of the quasi-two-dimensional heavy fermion superconductor CeCoIn5 have been investigated by microwave surface impedance measurements over a wide range of microwave frequencies and temperatures. We derive a value penetration depth lambda(0) similar to 190 nm, with a strong linear term in the temperature dependence of lambda(T) below T-c/3, consistent with a superconducting gap with line nodes. The real part of the conductivity displays a broad peak at low temperatures consistent with a decreased scattering rate of almost 2 orders of magnitude below T-c. CeCoIn5 has remarkably similar properties to those of the high-T-c cuprates.