Too powerful to be true. What can Google's Willow chip really do?

In early December 2024, Google Quantum AI unveiled a new chip for quantum computing - Willow. The presentation placed a strong emphasis on its high performance: the processor is faster than the most powerful modern supercomputer and can tackle a key industry problem that has remained unresolved for the last 30 years - quantum error correction. Moreover, Willow partially supports the many-worlds interpretation of quantum mechanics.

The many-worlds interpretation of quantum mechanics suggests that each quantum event creates parallel universes. For instance, if a particle has several possible paths, the universe "branches," and in each branch, the particle chooses one of them. All these parallel universes exist simultaneously, but we perceive only the one we inhabit.

However, among industry representatives, the emergence of the new processor did not generate the hype created by the media. Scientists and professionals in the field of quantum computing received Willow with little enthusiasm, viewing it as another important step in the development of quantum technologies. For them, Willow is a good processor, but not the revolutionary breakthrough the media has portrayed it to be.

Exaggerating the significance of new products is a common practice in the tech world. Whether it's the launch of a new iPhone or a quantum computing chip, they are all touted as "the best in history." Google is no exception, presenting yet another achievement as the major breakthrough of the decade.

Despite the grandiosity of the presentation, Willow's achievements should not be undervalued. The new chip from Google has drawn attention to the rapidly evolving industry and represents another step toward a world where calculations based on quantum mechanics might become commonplace.

What Google actually showcased with its Willow chip and how quantum computers, which are already sparking a real race among nations, might change the world.

How Quantum Computers Work and Why Willow Wasn't a Sensation

Quantum computers operate based on the principles of quantum mechanics, which fundamentally distinguishes them from traditional computers or smartphones. The primary difference is that instead of conventional bits, which can only have a value of 0 or 1, quantum computers use qubits (quantum bits).

Qubits, thanks to the phenomenon of superposition, can exist simultaneously in states 0, 1, or their combinations. This enables quantum computers to process a vast number of possibilities at once, providing them with significantly greater computational power compared to regular computers.

Moreover, the actual advantage of a quantum computer grows exponentially. For example, the performance of eight qubits in a quantum computer exceeds that of a conventional computer by 32,768 times.

"Quantum computing is, to some extent, a new stage in technological evolution. For the first time, we are transitioning from binary logic to quantum logic, bringing us closer to the principles of computations that occur in nature itself," explains Nikolai Maksimenko, co-founder of the startup Haiqu, which develops software for quantum computers.

Over the last few decades, quantum computing has evolved from a theoretical concept to a full-fledged industry with billions in investments. Key players in this market include Google, IBM, Microsoft, Amazon, and Intel.

Even in this complex field, which is still relatively unknown to the general public, fierce competition prevails, pushing companies to regularly demonstrate significant progress. Google, with its quantum chip Willow, is no exception.

Thus, the real sensation of the past week was the announcement regarding Willow's computational capabilities. According to Google, this chip can solve a problem in five minutes that would take the fastest supercomputers 10 septillion (a number with 21 zeros) years.

The founder of the Google Quantum AI team, Hartmut Neven, even suggested that such figures might indicate that computations are happening "in many parallel universes simultaneously."

However, as is often the case, the devil is in the details. The bold claims from the company have generated skepticism from parts of the scientific community. The question lies in how quantum supremacy is measured. Google uses a test called "random circuit sampling," in which the quantum computer performs a series of random operations and generates a distribution of random numbers. The idea is to show that the quantum computer does this faster than a classical supercomputer.

The issue is that this test is not a true algorithm in the classical sense. "Algorithms typically work with real input data, transforming them into useful results. In the case of Willow, the algorithm is merely a set of random operations and the outcome of random binary numbers," says Maksimenko.

As a result, Google's new quantum chip has also faced criticism from scientists regarding the multiverse theory. Some scientists, including American theoretical astrophysicist and science writer Ethan Siegel, believe the results of Willow are random and do not connect it to the idea of parallel universes.

Interestingly, in 2019, Google had already claimed quantum supremacy with its previous processor Sycamore, which completed a task (random number generation) in 200 seconds, while a classical supercomputer would take 10,000 years to do the same.

However, later IBM provided evidence that the world's most powerful supercomputer could nearly keep pace with Google's new quantum machine.

One of the key points of the Willow presentation was the demonstration of an algorithm that allows the creation of one logical bit based on many physical quantum bits. Google notes that this aggregated qubit turned out to be significantly more stable than each individual physical qubit.

In fact, the implementation of the logical qubit is an important step forward, confirming the possibility of overcoming the limitations of physical quantum bits and paving the way for more reliable quantum computing.

However, Maksimenko believes that IBM's Heron chip is similar to Willow in certain parameters and even surpasses it in some areas. "It can be expected that IBM will soon present its implementation of the logical qubit. Given the open access to IBM's quantum computer for researchers, we may see this result in the coming weeks," explains the co-founder of Haiqu.

The Revolution is Canceled

The presentation of Willow and the additional publication of research in the journal Nature did not surprise the scientific community much. The developments from the Quantum AI division had been known since the summer of this year. But in the media space, the Google team chose to announce itself more loudly.

The excitement and discussions surrounding the new "breakthrough" quantum processor led to a rise in Alphabet's shares, Google's parent company, by 25% from September's low. The day after the presentation, Alphabet's market capitalization narrowed its gap with the other "Big Seven" companies (Apple, Microsoft, Amazon, Nvidia, Meta, and Tesla).

The heated topic of quantum computing also influenced the stock prices of other projects related to quantum technologies, such as Rigetti Computing Inc. or D-Wave Quantum Inc.

However, the actual results and impact of Willow on the industry are somewhat more modest. "Those who follow progress in the field of quantum computers understand that achievements in this area are the result of gradual technological advancements, without any magic or influence from parallel worlds. This progress is based on years of work by experimentalists and theorists at Google, who have been able to double the number of qubits and improve their stability fivefold," notes Maksimenko.

It is still too early to talk about the rapid and full integration of quantum computers into human life. Most of them are bulky and resemble futuristic lamps or installations from science fiction: a huge cylinder with numerous copper wires, tubes, and gold plates stretching from the ceiling to the floor. This is a cryostat, which cools the qubits to temperatures close to absolute zero (-273.16 degrees Celsius).

Overall, the quantum computing industry is undergoing a gradual evolution. Work is being done not only on the "hardware" but also on software.

For instance, the startup Haiqu, in collaboration with the British bank HSBC, has developed an algorithm that allows for the loading of real data, such as from financial markets, onto a quantum computer at scales that already have practical benefits. This involves working with dozens or even hundreds of qubits, which was previously impossible.

The algorithm enables financial institutions, such as banks, to take the first step towards calculations on quantum computers,