Ultrafast mechanisms of radiation detection in granular YBaCuO films are studied in the wide wavelength range from millimeter waves to near infrared. With an increase in radiation frequency, the Josephson detection at the grain-boundary weak links is replaced by electron heating into the grains. This change occurs in the submillimeter wavelength range. The electron-phonon relaxation time tau /sub eph/ is determined from direct measurements, quasi-stationary electron heating measurements, and the frequency dependence of the current at which maximum voltage shift is observed. The temperature dependence of tau /sub eph/ at T>or=40 K was found to be tau /sub eph/ approximately T/sup -1/. The results show that detectors with a response time of a few picoseconds at nitrogen temperature are attainable.
展开▼
机译：在从毫米波到近红外的宽波长范围内，研究了颗粒状YBaCuO薄膜中辐射检测的超快机制。随着辐射频率的增加，晶粒边界薄弱环节的约瑟夫森检测被电子加热到晶粒中所取代。这种变化发生在亚毫米波长范围内。电子声子弛豫时间tau / sub eph /由直接测量，准静态电子加热测量以及观察到最大电压漂移的电流的频率依赖性确定。发现在t≥40K时tau / sub eph /的温度依赖性为tau / sub eph /约T / sup -1。结果表明，在氮气温度下具有几皮秒响应时间的检测器是可以实现的。
展开▼
