Google scientists announced on Wednesday that they have reached a significant milestone in their quest to produce functional quantum computing, with a new study demonstrating that they have lowered the mistake rate — a longstanding impediment for the much-hyped technology.
Quantum computing has been hailed as a revolutionary breakthrough that utilises our expanding scientific knowledge of the subatomic realm to develop a machine with capabilities far above those of ordinary computers.
Unfortunately, the technology remains mostly theoretical, with numerous thorny obstacles – including stubbornly high error rates – remaining in the way.
In recent research published in Nature, the Google Quantum AI group outlined a technique that can drastically reduce error rates.
This might give the US tech giant an advantage over competitors like IBM, which is also developing superconducting quantum processors.
Whereas conventional computers process information using bits that can be represented by either 0 or 1, quantum computers use qubits, which can be both simultaneously.
This phenomenon, known as superposition, enables a quantum computer to concurrently calculate an enormous number of alternative possibilities.
The computers utilise some of the most baffling parts of quantum mechanics, such as the phenomena known as ” entanglement,” in which two members of a pair of bits can exist in a single state even if they are physically separated.
As the qubits leave their quantum state and come into touch with the outside world, a condition known as decoherence can cause them to lose their information.
Its fragility results in significant mistake rates, which grow as the number of qubits increases, discouraging scientists who wish to expand their research.
Yet, Google’s team claimed to have proved for the first time in practise that a system employing error-correcting code can discover and rectify problems without altering the data.
The method was first theorised in the 1990s, but past attempts resulted in more errors, not fewer, according to Google co-author Hartmut Neven.
Neven stated during a press conference, “But if all components of your system have sufficiently low error rates, then the magic of quantum error correction kicks in.”
Julian Kelly, another co-author of the study, lauded the breakthrough as a “major scientific achievement,” stating that “quantum error correction is the most crucial technology for the future of quantum computing.”
Neven stated that the outcome was still insufficient and that the mistake rate must be reduced to an absolute minimum.
He noted that “there are additional measures to be taken” in order to realise the dream of a functional quantum computer.
Google said in 2019 that it had achieved “quantum supremacy” after its Sycamore machine completed a calculation in 200 seconds that would have taken a normal supercomputer 10,000 years to accomplish.
The accomplishment has since been contested, with Chinese academics claiming a supercomputer could have beaten Sycamore’s performance last year.