Scientists have devised a way to remove errors from future quantum computers using the famous “Schrödinger’s cat” thought experiment.
The new method encodes quantum information into antimony atoms. Antimony atoms have eight possible states, allowing them to store data more securely than standard two-state qubits (qubits).
This breakthrough is an important step toward making errors less likely to occur in quantum systems and easier to detect and correct when they occur, a key barrier to quantum computer development. I am. The researchers published their findings in the journal Nature Physics on Wednesday (January 14).
His thought experiment, first devised by physicist Erwin Schrödinger in 1925, imagines a cat placed inside an opaque box containing a vial of poison with an opening mechanism controlled by radioactive decay. An evocative explanation of the strange rules of the quantum world. This is a completely random quantum process.
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Schrödinger argued that until he opened the box and observed the cat, the laws of quantum mechanics meant that the unfortunate cat would exist in a simultaneous dead and alive state. .
In the case of qubits, the quantum information associated with the 0 or 1 states of classical computers can be encoded into the “spin-up” and “spin-down” states of atoms. Spin is the intrinsic angular momentum of an atom. Basic particles.
But if noise in a quantum computer suddenly changes this spin (as it often does), the quantum state is lost, errors occur, and the information inside is destroyed.
To get around this problem, researchers in the new study embedded antimony atoms with eight different spin orientations inside a silicon quantum chip. The six additional spin directions of the antimony atom (obtained by the compound nature of the atom that adds multiple individual spins) mean that, unlike a two-spin state system, a single error alone cannot convey the encoded information. It means not enough to destroy.
“As the saying goes, a cat has nine lives. One small scratch is not enough to kill a cat,” said co-author, University of New South Wales (UNSW) Department of Electrical Engineering and Telecommunications in Australia. Benjamin Wilhelm, a doctoral student at said in a statement. “Our metaphorical ‘cat’ has seven lives. It takes seven consecutive errors to turn ‘0’ into ‘1.’”
With the system in place, the researchers say they will now work to demonstrate how to detect and correct errors in chips, considered the “holy grail” in quantum computing.
“When an error occurs, we can detect it quickly and correct it before more errors accumulate.Continuing with the ‘Schrödinger’s cat’ analogy, it’s like having our cat in our face. It’s like seeing someone come home with a big scar,” author Andrea Morello, professor of electrical engineering and quantum physics at UNSW University, said in a statement. “He’s not dead yet, but we know he got into a fight. We’re going to find out who started the fight before it happens again and my cat gets hurt more.” You can.”
