Self-Pumped Josephson Parametric Amplification

Abstract

Parametric gain has been demonstrated at 30 MHz using the nonlinear inductance of Josephson point‐contact devices. SQUID‐type configurations were used to achieve degenerate‐mode negative‐resistance amplification with self‐pumping achieved via the internal Josephson oscillations. Gain as large as 11 dB was measured. The small‐signal analysis predicts parametric amplification and delineates the importance of the critical current, circuit loss, and circuit coupling efficiency.