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Low-noise microwave amplifiers are crucial for detecting weak signals infields such as quantum technology and radio astronomy. However, designing anideal amplifier is challenging, as it must cover a wide frequency range, addminimal noise, and operate directionally - amplifying signals only in theobserver's direction while protecting the source from environmentalinterference. In this work, we demonstrate that an array of non-linearlycoupled Josephson parametric amplifiers (JPAs) can collectively function as adirectional, broadband quantum amplifier by harnessing topological effects. Byapplying a collective four-wave-mixing pump with inhomogeneous amplitudes andlinearly increasing phase, we break time-reversal symmetry in the JPA array andstabilize a topological amplification regime where signals are exponentiallyamplified in one direction and exponentially suppressed in the opposite. Weshow that compact devices with few sites $N\sim 11-17$ can achieve exceptionalperformance, with gains exceeding 20 dB over a bandwidth ranging from hundredsof MHz to GHz, and reverse isolation suppressing backward noise by more than 30dB across all frequencies. The device also operates near the quantum noiselimit and provides topological protection against up to 15% fabricationdisorder, effectively suppressing gain ripples. The amplifier's intrinsicdirectionality eliminates the need for external isolators, paving the way forfully on-chip, near-ideal superconducting pre-amplifiers.

Topological Josephson parametric amplifier array: A proposal for directional, broadband, and low-noise amplification