The second- and third-order nonlinear microwave response of a superconducting YBa2Cu3O7 thin-film resonator was synchronously measured using three input tones. This technique permits the local measurement, and hence mapping, of intermodulation distortion inside the resonator. Second- and third-order IMD measured with a fixed probe relaxed in remarkably different ways after the removal of a static magnetic field. The second-order IMD relaxed by two different magnetic processes, a fast process that appears related to bulk remanent magnetization and a slow process that fits the description of Bean and Livingston. The third-order IMD relaxes by only one process that is distinct from the two processes controlling second order relaxation.
R. A. Huizen, S. L. Hamilton, G. T. Lenters and S. K. Remillard, "Relaxation of Microwave Nonlinearity in a Cuprate Superconducting Resonator," in IEEE Transactions on Applied Superconductivity, vol. 27, no. 4, pp. 1-5, June 2017. doi: 10.1109/TASC.2016.2638404 URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7779078&isnumber=7753032