Intermodulation distortion (IMD) of microwave signals incident upon a superconducting YBa₂Cu₃O_7−x thin film sample on a LaAlO₃ substrate is shown to relax as the sample magnetization also relaxes, revealing the signature of fluxon decay in the microwave distortion. The sample contained a microchannel of columnar defects that was introduced using heavy ion beam irradiation. After exposure to and then removal of a low strength static magnetic field, IMD relaxed due to thermal activation of fluxons over the surface barrier. This process influenced second and third order IMD differently, visible in the differing functional form of the IMD in time and the temperature dependence of the relaxation function. The presence of columnar defects in the test sample suppressed thermal activation by pinning of fluxons, notably with complete suppression of relaxation in third order IMD at low temperatures. Higher order IMD was found to relax with the same functional form as the second and third order IMD of the same parity.

入射到LaAlO ₃上的超导YBa ₂ Cu ₃ O _{7− x}薄膜样品上的微波信号的互调失真（IMD）当样品的磁化强度也松弛时，显示基片松弛，从而揭示了微波畸变中的通量衰减特征。样品包含柱状缺陷的微通道，该通道使用重离子束辐照引入。暴露于低强度静磁场后再去除后，由于通量在表面势垒上方热活化，IMD放松了。此过程对二阶和三阶IMD的影响不同，在时间上和松弛函数的温度依赖性上，以IMD的不同功能形式可见。测试样品中柱状缺陷的存在抑制了通量钉扎的热活化，特别是在低温下完全抑制了三阶IMD中的弛豫。