ab-plane surface impedance of the single-layer cuprate Tl2Ba2CuO6+delta

The ab-plane surface impedance of TI2Ba2CuO6+delta (T1-2201) has been measured at 14.4, 24.8 and 35.9 GHz using cavity perturbation techniques. The result of these measurements is a picture of the superconducting electrodynamics of T1-2201 that closely resembles those of YBa2Cu3O7-delta and Bi2Sr2CaCu2O8. Here we describe the main features of our measurements; in particular, we see a linear temperature dependence of the in-plane penetration depth at low temperature, consistent with an unconventional pairing state with line nodes. The simple crystal structure of T1-2201 (tetragonal, with a single CuO2 plane/unit cell) makes this an interesting addition to our knowledge of cuprate electrodynamics.