A laser scanning microscope with a thermal spot size of about 4 μm is used to measure a quantity proportional to the rf current density in an operating superconducting co-planar waveguide microwave resonator. The twinning of the LaAlO3 substrate produces a meandering of the current at the edges due to irregularities in the wet etching of the YBa2Cu3O7−δ film associated with substrate twin domain blocks, and a (∼ 20%) enhancement of the rf photoresponse at these locations. These irregularities are candidates for enhanced nonlinear response from the device. The effects of substrate twinning and the resulting edge features on the superconducting film are discussed and analyzed.
@article{arxiv.cond-mat/0209614,
title = {Effect of LaAlO$_3$ Surface Topography on RF Current Distribution in Superconducting Microwave Devices},
author = {A. P. Zhuravel and A. V. Ustinov and H. Harshavardhan and Steven M. Anlage},
journal= {arXiv preprint arXiv:cond-mat/0209614},
year = {2009}
}
Comments
13 pages, 4 figures, submitted to Applied Physics Letters