Advanced Concepts in Josephson Junction Reflection Amplifiers

Abstract

Low-noise amplification atmicrowave frequencies has become increasingly important for the research related to superconducting qubits and nanoelectromechanical systems. The fundamental limit of added noise by a phase-preserving amplifier is the standard quantum limit, often expressed as noise temperature $T_q=\hslash \omega /2k_B$. Towards the goal of the quantum limit, we have developed an amplifier based on intrinsic negative resistance of a selectively damped Josephson junction. Here we present measurement results on previously proposed wide-band microwave amplification and discuss the challenges for improvements on the existing designs. We have also studied flux-pumped metamaterial-based parametric amplifiers, whose operating frequency can be widely tuned by external DC-flux, and demonstrate operation at $2\omega$ pumping, in contrast to the typical metamaterial amplifiers pumped via signal lines at $\omega$.

9 pages, 6 figures

References in corpus (4)

• Amplification and squeezing of quantum noise with a tunable Josephson metamaterial
• Nanomechanical motion measured with precision beyond the standard quantum limit
• A widely tunable parametric amplifier based on a SQUID array resonator
• Input Impedance and Gain of a Gigahertz Amplifier Using a DC SQUID in a Quarter Wave Resonator

Cited by in corpus (1)

• Implementation of traveling odd Schr$\ddot{o}$dinger cat states in circuit-QED