Time-multiplexed amplification in a hybrid-less and coil-less Josephson parametric converter

TL;DR

This paper presents a simplified, on-chip Josephson parametric converter that eliminates bulky external components and demonstrates time-multiplexed amplification, enhancing scalability for quantum computing applications.

Contribution

The authors introduce a novel JPC design with on-chip pump and flux biasing, reducing size and complexity while enabling time-multiplexed microwave amplification.

Findings

Achieved a compact, hybrid-less, coil-less JPC with comparable performance to traditional devices.

Demonstrated time-multiplexed amplification of microwave signals separated by more than the device bandwidth.

Showcased potential for high-fidelity, time-multiplexed qubit readout.

Abstract

Josephson parametric converters (JPCs) are superconducting devices capable of performing nondegenerate, three-wave mixing in the microwave domain without losses. One drawback limiting their use in scalable quantum architectures is the large footprint of the auxiliary circuit needed for their operation, in particular, the use of off-chip, bulky, broadband hybrids and magnetic coils. Here, we realize a JPC which eliminates the need for these bulky components. The pump drive and flux bias are applied in the new device through an on-chip, lossless, three-port power divider and on-chip flux line, respectively. We show that the new design considerably simplifies the circuit and reduces the footprint of the device while maintaining a comparable performance to state-of-the-art JPCs. Furthermore, we exploit the tunable bandwidth property of the JPC and the added capability of applying alternating currents to the flux line in order to switch the resonance frequencies of the device, hence demonstrating time-multiplexed amplification of microwave tones that are separated by more than the dynamical bandwidth of the amplifier. Such a measurement technique can potentially serve to perform time-multiplexed, high-fidelity readout of superconducting qubits.