Quantum-limited Josephson parametric amplifier for fast quantum microwave measurements

LTL Quantum Physics Seminar (Nanotalo). Speaker: Mr. Michael Perelshtein (Moscow Institute of Physics and Technology, Russia).

There has been growing need to detect weak microwave signals at the level of one photon in recent years. Moreover, detection should occur over a wide range of frequencies. A parametric amplifier using a nonlinear Josephson element can solve this problem. Recently, several designs have been offered by many groups around the world, but all of them have either insufficient characteristics (bandwidth at the level of 10 MHz) or are difficult to produce (traveling wave designs containing 2000 identical Josephson contacts). We present a design which is relatively simple to manufacture in a single lithography step. While design optimization is still on-going, our sample already shows good results: maximum gain of 17dB and maximum bandwidth of about 200 MHz.