Superconducting quantum interference devices (SQUIDs) are state-of-the-art in ultrasensitive magnetometry; however, conventional SQUIDs are fundamentally limited by the inherently nonlinear, periodic nature of their transfer function. Although flux-locked loop configurations can mitigate this issue, they introduce electronic complexity and bandwidth constraints that hinder scalability in quantum circuits. In this work, we present an experimental demonstration of the bi-SQUIPT, a flux transducer that modulates the density of states in a proximitized superconducting weak link. The device employs a dual-loop architecture with differential readout, which enables cancellation of nonlinearities typical of individual elements, achieving a voltage swing of approximately $120\mathrm{\mu }\mathrm{V}$. Measurements yield a spurious-free dynamic range of up to 60 dB, consistent with theoretical predictions and comparable to that of SQUID arrays, while maintaining femtowatt power dissipation. The results further highlight a remarkable operational stability up to 600 mK, positioning the bi-SQUIPT as an enabling technology for high-density cryogenic quantum electronics.

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• Josephson effect
• Proximity effect
• Quantum interference effects
• Quantum transport
• SNS junctions
• Superconducting devices
• Transducers
• Transistors