December 9, 2022

Superconducting artificial giant atoms for Quantum Computing

MIT researchers have introduced a quantum computing architecture that can perform low-error quantum computations while also rapidly sharing quantum information between processors.

While natural atoms are small and point-like with respect to the wavelength of light they interact with, the researchers have showed that this need not be the case for superconducting “artificial atoms.” Instead, they have constructed “giant atoms” from superconducting quantum bits, or qubits, connected in a tunable configuration to a microwave transmission line, or waveguide.

This allows the researchers to adjust the strength of the qubit-waveguide interactions so the fragile qubits can be protected from decoherence, or a kind of natural decay that would otherwise be hastened by the waveguide, while they perform high-fidelity operations. Once those computations are carried out, the strength of the qubit-waveguide couplings is readjusted, and the qubits are able to release quantum data into the waveguide in the form of photons, or light particles.

The system realized by the researchers represents a new regime of light-matter interactions, the researchers say. Unlike models that treat atoms as point-like objects smaller than the wavelength of the light they interact with, the superconducting qubits, or artificial atoms, are essentially large electrical circuits. When coupled with the waveguide, they create a structure as large as the wavelength of the microwave light with which they interact.

The work represents a key advance toward a complete quantum computing platform. (

The paper has been published in Nature.

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