A power-adjustable superconducting terahertz source utilizing electrical triggering phase transitions in vanadium dioxide

We report a practical superconducting terahertz (THz)source, comprising a stack of Bi2Sr2CaCu2O8 intrinsicJosephson junctions (IJJs) and a vanadium dioxide (VO2) tunableattenuator with coplanar interdigital contacts. The electrical triggeringphase transitions are observed not only at room temperature, but also at low temperatures, which provides a proof of the electrical triggering. Applying this, the VO2attenuator is implemented for the independent regulations on the emission powers from the IJJ THz emitter, remaining frequencies and temperatures unchanged. Theattenuation can be tuned smoothly and continuously within a couple of volts among which the maximum is, respectively, −5.6 dB at 20 K or −4.3 dB at 25 K. Such a power-adjustable radiationsource, including the VO2attenuator, can further expand its practicability incryogenic THz systems, like superconducting THz spectrometers.

Source: Applied Physics Letters - December 5, 2016 Category: Physics Authors: L. Y. Hao, X. J. Zhou, Z. B. Yang, H. L. Zhang, H. C. Sun, H. X. Cao, P. H. Dai, J. Li, T. Hatano, H. B. Wang, Q. Y. Wen and P. H. Wu Source Type: research