The characterization of the system indicated a few main limits, although. Cat qubits make bit flips extraordinarily unlikely, however not unimaginable. By focusing error correction solely on part flips, any bit flips that do happen inescapably set off the failure of the whole logical, error-corrected qubit. “Attaining lengthy logical bit-flip instances is difficult as a result of any single cat qubit bit flip occasion in any a part of the repetition code immediately causes a logical bit flip error,” the authors word. The opposite difficulty is that the transmons used for error correction nonetheless endure from each bit and part flips, which may additionally mess up the whole error-corrected qubit.
The place does this depart us?
There are a selection of corporations like Amazon which can be betting that utilizing a in some way much less error-prone {hardware} qubit will enable them to get efficient error correction utilizing fewer complete {hardware} qubits. In the event that they’re right, they’re going to be capable of construct error-corrected quantum computer systems utilizing far fewer qubits, and so doubtlessly carry out helpful computation sooner. For them, this paper is a vital validation of the concept. You are able to do a type of mixed-mode error correction, with a strong {hardware} qubit paired with a compact error-correction code.
However past that, the messages are fairly combined. The {hardware} nonetheless needed to depend on much less strong {hardware} qubits (the transmons) to do error correction, and the very low error price was nonetheless not low sufficient to keep away from having occasional bit flips. And, finally, the error price enhancements gained by growing the scale of the logical qubit aren’t on a trajectory that will get you a helpful degree of error correction while not having an unrealistically giant variety of {hardware} qubits.
Briefly, the underlying {hardware} is not at the moment adequate to allow any type of complicated calculation, and it could want radical enhancements earlier than it may be. And there is not an apparent alternate path to efficient error correction. The potential of this method continues to be there, however it’s not apparent how we’ll construct {hardware} that lives as much as that potential.
As for Amazon, the image is even much less clear, provided that that is the second qubit know-how that it has talked about publicly. It is unclear whether or not the corporate goes to go all-in on this method, or continues to be searching for a know-how that it is keen to decide to.
Nature, 2025. DOI: 10.1038/s41586-025-08642-7 (About DOIs).
