论文标题
柱状缺陷对超导YBCO谐振设备微波非线性的磁性松弛的影响
Influence of Columnar Defects on Magnetic Relaxation of Microwave Nonlinearity in Superconducting YBCO Resonator Devices
论文作者
论文摘要
在Laalo3底物上的超导YBA2CU3O7薄膜样品中，微波信号的间调节失真（IMD）显示出在样品磁化方面放松，揭示了微波失真中Fluxon衰减的特征。该样品包含使用重离子束照射引入的柱状缺陷的微通道。暴露于低强度的静态磁场后，IMD由于磁通量在表面屏障上的热激活而放松。该过程对IMD的二阶和三阶影响不同，以IMD的不同功能形式以及弛豫函数的温度依赖性可见。测试样品中柱状缺陷的存在通过固定磁通量抑制了热激活，特别是在低温下以三阶IMD抑制了弛豫。发现高阶IMD的功能形式与相同奇偶校验的第二和三阶IMD相同。
Intermodulation distortion (IMD) of microwave signals incident upon a superconducting YBa2Cu3O7 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.
