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Updated: Apr 30, 2026

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
Josephson directional amplifier for quantum measurement of superconducting circuits
Baleegh Abdo1, Katrina Sliwa1, S Shankar1
1Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA.
Abstract:
We realize a microwave quantum-limited amplifier that is directional and can therefore function without the front circulator needed in many quantum measurements. The amplification takes place in only one direction between the input and output ports. Directionality is achieved by multipump parametric amplification combined with wave interference. We have verified the device noise performances by using it to read out a superconducting qubit and observed quantum jumps. With an improved version of this device, the qubit and preamplifer could be integrated on the same chip.
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