After fundamentally changing science more than a century ago, modern physics may be about to revolutionize the world of computers – with implications for everything from the speed of doing complex research to nations’ vulnerability to cyberattack.
Billions of dollars are pouring into quantum computing – a budding field that relies on the sometimes surprising behavior of subatomic particles to process information. This past week in Boston, Quantum.Tech World was held, with over 1,000 top executives and researchers from more than 40 countries gathering to transition the ideas from the lab to the commercial market.
The White House has recognized the potential for quantum computing. President Donald Trump this week signed executive orders pushing for the creation of a quantum computer for scientific research, use of quantum science by the military, and protections for government computers against quantum cyberattacks by U.S. rivals.
Why We Wrote This
The United States and China are racing to develop computers based on the properties of quantum physics – with implications for science and security.
If a technological breakthrough comes, wide-ranging implications will likely follow. Quantum computing poses potential benefits for the academic and business worlds, but also raises cybersecurity concerns, as it could be used to crack security codes that protect computers from hacking.
It might still take years for current quantum computers to reach an adequate level of development. However, higher capital investment and assistance from artificial intelligence have accelerated progress.
“Quantum technology is a really exciting area. It has the potential for major advances,” says Steven Olmschenk, an associate professor at Denison University in Granville, Ohio, who researches atomic physics and quantum information. “The path that it takes [to get there] is not completely clear, or how long those things will take … but I think we are definitely on the path to realizing that future.”
What are quantum computers?
Hailed as technology that can compute what’s currently impossible, quantum computers are a variation of computers used today. At their core is a quantum processing unit (QPU), their version of a classical computer’s central processing unit.
A classical computer stores information as bits, each being either a 1 or a 0. Quantum computers store information as qubits, where each can be 1, 0, or a combination of both at the same time, called “superposition.”
With superposition, qubits can exist in multiple states at the same time. One can think of it as similar to a coin flip. In our everyday world, when someone flips a coin, it must land on heads or tails. But if this coin were in a state of superposition, the result would be a combination of probabilities that the coin is heads or tails – it wouldn’t be just one or the other.
This ability of qubits to have multiple states could allow a quantum computer to yield a range of solutions, all at once, while a classical computer has to go through each calculation one by one.
Outputs in quantum computers also depend on what’s known as quantum entanglement, which causes the condition of one qubit to depend on that of another. For instance, if two qubits are entangled, and one of them is revealed (as “heads” in the coin toss analogy), we would know the outcome of the other qubit (as “tails”), even before it is revealed. This helps quantum computers explore many possible solutions to a problem much more efficiently than classical computers.
Creating and maintaining states of superposition and entanglement are the main engineering challenges behind building these computers, as qubits operate on subatomic levels. But once these challenges are overcome, harnessing a network of qubits can yield stunning numbers of outcomes. With 80 ideal qubits together, a QPU could do more calculations at once than there are grains of sand on Earth.
Where does current technology stand?
Dozens of companies, including IBM, Google Quantum AI, IonQ, and Quantinuum, have already created quantum computers, but so far, there is no clear leader in development.
There is also more than one way to create quantum computers. Each company uses different elementary particles or methodologies to build these computers or QPUs, so it is unclear what form future quantum computers might take.
Currently, the most advanced quantum computers use anywhere from hundreds of qubits to the low thousands. These machines are delicate and prone to faults. Still, with clever coding even faulty qubits can be optimized to create a high-performance system.
“We call that quantum error correction,” says Niklas Mueller, an assistant professor and researcher at the University of New Mexico in Albuquerque. “That is currently the big frontier.”
AI models might accelerate the development of quantum computing. They are especially useful at helping with quantum error correction, because AI can help code and pinpoint errors within noisy QPUs much faster than traditional methods.
While significant strides have been made, these computers have yet to sufficiently demonstrate full quantum advantage – the ability to deliver savings in resources or achieve higher accuracy compared with classical computing methods.
What are quantum computing’s potential uses?
Although quantum computing is unlikely to ever fully replace current technology, its implications are varied.
Quantum computing could be significantly useful in areas such as chemistry and materials science. According to global technology and consulting company IBM, quantum computing is especially helpful in modeling physical systems and discovering patterns and structures in data that might otherwise be missed. That could be useful in sectors from biology to finance.
Quantum computing could also be used to optimize supply chains, as it could find efficiencies by sifting quickly through thousands of pathways.
But quantum computing could also pose security risks to modern encryption systems. In 1994, mathematician Peter Shor developed Shor’s algorithm, a method that could be used by quantum computers to crack RSA encryption, which secures much of today’s online communication. While classical computers would take millions of years to crack a frequently used RSA encryption, quantum computers could do so in just days.
To counter this, the United States has spearheaded a Post-Quantum Cryptography Initiative, which led to the development of new encryption algorithms expected to be released as standards for civilian and defense networks by 2027.
Various parties see quantum computing’s potential, as evidenced by a recent $10 billion commitment by IBM. The consulting firm McKinsey & Co. has predicted the industry will be worth as much as $1.3 trillion by 2035.
As with AI and other technology, China and the U.S. are rivals in the development race. China has recently focused more investment in quantum computing, and designed the world’s first dual-core atomic quantum computer.
The Trump administration committed $2 billion to nine quantum computing firms, which included equity investments through the Commerce Department in late May. Mr. Trump’s executive orders this week to accelerate the sector, too, attempt to position the U.S. ahead of China.
These computers, however powerful, will likely solve different problems than classical computers solve, Dr. Mueller says.
“[Quantum computing] doesn’t mean, ‘OK, I’m upgrading my laptop now to a quantum laptop, and you just start to surf the internet,’” he says. “We’re solving different problems with quantum computers, and probably some problems that we don’t even dare to try to solve right now.”