Quantum control of an oscillator using a Josephson circuit

Optical image of the device used by the researchers in their study. Credit: Vrajitoa

A team of researchers at Princeton University, Northwestern University and the University of Chicago have directly operated an oscillator using a stimulated Josephson nonlinearity. In their paper, published in Nature Physics, the team achieved quantum control of an oscillator by operating it as an isolated two-level system, tailoring its Hilbert space.

The scientists have been trying to come up with clever strategies to engineer microwave cavities as effective two-level systems. The method they proposed in their paper could allow researchers to harness some of the properties of these cavities, including their improved photon lifetimes, by introducing a new kind of nonlinearity.

This new approach could have important implications for the development of new architectures quantum computing with superconducting circuits. Their work ultimately offers an alternative and highly promising path for engineering a variety of highly coherent anharmonic oscillators in a hardware efficient manner, using a single Josephson coupler circuit. (Phys.org)

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