We have studied the effect of a dc electric field on the effective microwave surface impedance of a thin film YBa2Cu3O 7/SrTiO3/YBa2Cu3O7 (YBCO/STO/YBCO) trilayer by a dielectric resonator technique. At large dc electric fields (≳105 V/cm), both the effective surface resistance and reactance of the sample decrease monotonically with increasing dc voltage applied to the to YBCO film, yielding at 25 K and 24.7 GHz ∥δRs/δVdc∥∼0.25 μΩ/V and ∥δXs/δVdc∥∼1.8 μΩ/V, respectively. A two-fluid analysis indicates that the changes in the surface impedance can be explained in terms of field induced changes in the superconducting carrier density of the top YBCO film.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)