Josephson Parametric Reflection Amplifier with Integrated Directionality

Abstract

Detecting faint light from deep space requires an excellent signal-to-noise ratio, as does quantum information processing. For microwave and terahertz frequencies, a simple directional amplifier offering minimal added loss and easy on-chip integration would be a major step forward. This study envisions such an amplifier as two Josephson-junction oscillators plus an on-chip passive circuit, promising 20 dB of gain while adding only ~1 photon s${}^{\ensuremath{-}1}$ Hz${}^{\ensuremath{-}1}$ of noise. This work addresses scale-up in circuit QED and detector research by integrating directional signal routing and amplification, allowing more qubits or pixels per unit area.