Yale physicists have developed a cat for error correction – a new device that combines Schrödinger’s concept of cats for superposition (a physical system that exists in two states at once) with the ability to correct some of the most complex errors in a calculation quantum.
Break Yale̵7;s recent breakthrough in trying to master and manipulate the physics needed for a useful quantum computer: Correcting the flow of errors that accumulate between fragile pieces of quantum information, called qubits, while performing a task.
A new study report on the discovery appears in the journal nature. The old author is Michel Devoret, Yale FW Beinecke professor of Physics and Applied Physics. The first authors of the study are Alexander Grimm, a former postdoctoral fellow at Devoret’s lab who is now a property management scientist at the Paul Scherrer Institute in Switzerland, and Nicholas Frattini, a graduate student at Devoret’s lab.
Quantum computers have the potential to transform an industry group, from pharmaceuticals to financial services, enabling calculations that are orders of magnitude faster than today’s supercomputers.
Yale – led by Devoret, Robert Schoelkopf and Steven Girvin – continues to build on the first two decades of quantum research. Yale’s approach to building a quantum computer is called a “QED circuit” and uses microwave light particles (photons) in an overlapping microwave resonator.
In a traditional computer, information is encrypted either 0 or 1. The only errors that accumulate during calculations are “bit turns” when a bit of information is accidentally rotated from 0 to 1 or vice versa. The way to correct it is by building on redundancy: using three “physical” pieces of information to provide an “effective” or accurate -.
In contrast, bits of quantum information – qubits – are subject to both bits and “slip phases”, in which a qub is randomly rotated between quantum assumptions (when two opposite states exist simultaneously).
So far, quantum researchers have tried to correct errors by adding greater redundancy, requiring an abundance of physical cubes for each effective cube.
Write the dome for the cat – named after Schrödinger’s cat, the famous paradox used to illustrate the concept of conjecture.
The idea is to put a cat in a sealed box with a radioactive source and a poison that will be stimulated if an atom of the radioactive substance rots. The theory of quantum physics assumption suggests that until someone opens the box, the cat is both alive and dead, an assumption of states. Opening the box to observe the cat causes it to suddenly change its quantum state at random, forcing it to be either alive or dead.
“Our work stems from a new idea. Why not use a clever way to encode information into a single physical system, so that some sort of error is typed directly?” Asked the Devoret.
Unlike the many physical cubes needed to maintain an effective dome, a single cat dome can prevent phase slips all by itself. The cat dome encodes an effective cube in the assumptions of two states within a single electronic circuit – in this case a superconducting microwave resonator whose oscillations correspond to the two states of the dome cats.
“We achieve all of this by applying microwave frequency signals to a device that is not significantly more complicated than a traditional overlay cube,” Grimm said.
The researchers said they are able to change their cat’s dome from any of its guessing states to any other guessing state, in command. Moreover, researchers created a new way to read or identify information encoded in the cube.
“This makes the system a new versatile element, which we hope will find its use in many aspects of quantum computation with superconducting circuits,” Devoret said.
The new device extends the life of quantum information
A. Grimm et al, Stabilization and operation of a Kerr-cat dome, nature (2020). DOI: 10.1038 / s41586-020-2587-z
Provided by Yale University
citation: Quantum researchers create cat for error correction (2020, August 12) taken on August 12, 2020 from https://phys.org/news/2020-08-quantum-error-correcting-cat.html
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