Advancements in the development of fully capable and practical quantum computer continue to progress rapidly, and Google researchers have recently announced a significant breakthrough in the capabilities of existing quantum machines.
Although we refer to these devices as quantum computers, they are essentially prototypes showcasing the potential of what quantum computers can become. Currently, they rely on highly specific and extreme conditions to operate, and maintaining stability and error-free performance is a challenge.
Despite these limitations, the computing power of quantum computers is constantly improving and becoming more impressive.
Google’s latest quantum system boasts a total of 70 operational qubits, which are the quantum counterparts of classical bits. Qubits can represent 1, 0, or both simultaneously, enabling certain calculations to be executed at astonishing speeds.
The team utilized a complex synthetic benchmark known as random circuit sampling, which involves extracting readings from randomly generated quantum processes. This approach maximizes the efficiency of critical operations, minimizing the risk of external disturbances disrupting the calculations. The researchers then estimated the time it would take for existing supercomputers to perform the same computations.
In their recent paper, the researchers state, “We conclude that our demonstration is firmly in the regime of beyond-classical quantum computation.”
According to their findings, the Frontier supercomputer, currently the most powerful computer in the world, would require over 47 years to complete the same calculations, whereas the Sycamore quantum computer accomplished it in a matter of seconds.
A similar experiment was conducted by a group including Google engineers in 2019, using 53 qubits. Just as before, debates persist regarding the practicality and usefulness of these specific simulations, as well as the fairness of comparing supercomputer performance to the achieved results.
Nonetheless, the Google team asserts that this milestone demonstrates quantum supremacy, signifying that quantum computers can indeed tackle processes that surpass the capabilities of even the fastest classical computers.
These new experiments also shed light on quantum noise, which refers to the inherent uncertainty and fragility within a quantum computer as it operates within the realm of probabilities. The research highlights how quantum noise can affect running processes and, in some cases, give rise to new phases or states within a quantum system.
Effectively dealing with this noise to accurately record qubit states is crucial for achieving proper functionality in quantum computers. Scientists have employed various approaches in the past to address this challenge.
Steve Brierley, CEO of UK-based quantum company Riverlane, views these latest experiments as another significant milestone in quantum computing research, stating that “the squabbling about whether we had reached, or indeed could reach, quantum supremacy is now resolved.”
While a paper detailing the new research is available on arXiv, it is important to note that it has yet to undergo peer review.
