Chalmers University of Technology, Gothenburg, S-41296, Sweden.
Nanoscale Res Lett. 2012 Apr 18;7(1):224. doi: 10.1186/1556-276X-7-224.
A novel concept of the two-dimensional (2D) array of cold-electron nanobolometers (CEB) with double polarised cross-dipole antennas is proposed for ultrasensitive multimode measurements. This concept provides a unique opportunity to simultaneously measure both components of an RF signal and to avoid complicated combinations of two schemes for each polarisation. The optimal concept of the CEB includes a superconductor-insulator-normal tunnel junction and an SN Andreev contact, which provides better performance. This concept allows for better matching with the junction gate field-effect transistor (JFET) readout, suppresses charging noise related to the Coulomb blockade due to the small area of tunnel junctions and decreases the volume of a normal absorber for further improvement of the noise performance. The reliability of a 2D array is considerably increased due to the parallel and series connections of many CEBs.Estimations of the CEB noise with JFET readout give an opportunity to realise a noise equivalent power (NEP) that is less than photon noise, specifically, NEP = 4 10-19 W/Hz1/2 at 7 THz for an optical power load of 0.02 fW.
提出了一种具有双极化交叉偶极天线的二维（2D）冷电子纳米热敏电阻（CEB）阵列的新概念，用于超灵敏多模式测量。这个概念为同时测量射频信号的两个分量提供了一个独特的机会，并且避免了为每个极化组合使用两种方案的复杂性。CEB 的最佳概念包括超导-绝缘体-正常隧道结和 SN Andreev 接触，这提供了更好的性能。这个概念允许与结栅场效应晶体管（JFET）读出更好地匹配，抑制与库仑阻塞相关的充电噪声，因为隧道结的面积较小，并且减小了正常吸收体的体积，以进一步提高噪声性能。由于许多 CEB 的并联和串联连接，2D 阵列的可靠性大大提高。使用 JFET 读出对 CEB 噪声的估计使我们有机会实现低于光子噪声的噪声等效功率（NEP），具体而言，对于 0.02 fW 的光功率负载，在 7 THz 处的 NEP = 4 10-19 W/Hz1/2。
