Practical quantum computers are moving closer to reality
Alexander Yakimov / Alamy
Fully practical quantum computers haven’t arrived yet, but the quantum computing industry is ending the year on an optimistic note. At the Q2B Silicon Valley conference in December, which brings together quantum business and science experts, the consensus seemed to be that the future of quantum computing is only getting brighter.
“On balance, we think it is more likely than not that someone, or maybe multiple someones, are going to be able to make a really industrially useful quantum computer, which is not something I thought I’d be concluding at the end of 2025,” said Joe Altepeter, programme manager for the US Defense Advanced Research Projects Agency’s Quantum Benchmarking Initiative (QBI) at a presentation during the conference. The goal of QBI is to determine which of the several currently competing approaches for building quantum computers can produce a useful device, which would also have to correct its own errors, or be fault-tolerant.
The programme will run for several years and involve hundreds of expert evaluators. Taking stock of the programme after its first six months, Altepeter said the team identified “huge obstacles” in the way of each of the approaches, but he also expressed surprise that this didn’t disqualify any of them from the race to produce a useful quantum device.
“In late 2025, it feels to me like all of the key hardware building blocks seem to be more or less in place, at roughly the required fidelity, maybe for the first time, leaving only these enormous questions about… the engineering challenges,” said Scott Aaronson at the University of Texas at Austin in another presentation. A respected expert and long-time commentator on the industry, Aaronson noted the ongoing challenges with identifying new algorithms that could lead to more practical uses for quantum computers, but described the recent progress in hardware development as “spectacular”.
There are good reasons to be excited about quantum computing hardware, but applications lag behind, said Google’s Ryan Babbush. At the conference, Google Quantum AI and several partners announced the finalists in the XPRIZE competition, which aims to change this.
The work of the seven finalists includes simulations of biomolecules relevant for human health, algorithms that could augment classical simulations of candidate materials for clean energy solutions and computations that may factor into diagnosis and treatment of diseases that have complex causes.
“A few years ago, I wasn’t that excited about running applications on quantum computers. I am getting more interested now,” said John Preskill at the California Institute of Technology, another significant scholar and defining voice within quantum computing. In his presentation, he made a case for near-term uses of quantum computers for scientific discovery.
In the past year, several quantum computers have in fact been used for computations in, for example, the physics of materials and high-energy particles, in a way that may soon rival or surpass the best traditional computing methods.
A handful of applications have traditionally been identified as particularly suitable for quantum computers, but here, too, there is work left to do. For instance, Pranav Gokhale at Infleqtion, a firm that builds quantum devices from extremely cold atoms, presented on a classic algorithm – Shor’s algorithm – that could be used to break much of the encryption used by today’s banks. The work represents the first implementation of a version of Shor’s algorithm on logical qubits – quantum computer components protected from errors. However, this demonstration was still nowhere near the computational complexity and computing power needed to allow for the easy decryption of encrypted information in the real world, underlining how significant hardware and software improvements are still necessary despite recent progress.
Dutch start-up QuantWare presented a possible solution to the industry’s big hardware challenge – making quantum computers larger, which would make them more computationally powerful, without making them less reliable. The firm’s quantum processor unit architecture promises to incorporate 10,000 qubits made from superconducting circuits, which is about a hundred times more than the currently most used superconducting quantum computers have. Matt Rijlaarsdam at QuantWare says the first devices of this size could be fully working within two-and-a-half years. Several other firms, such as IBM and Quantinuum, aim to build large quantum computers on a similar timescale, while QuEra plans on 10,000 qubits made from ultracold atoms within just a year, so competition will be as fierce as the engineering challenges.
And the industry is only projected to keep growing, from $1.07 billion in global investments in 2024 to about $2.2 billion in 2027, according to a survey of the quantum computing industry conducted by Hyperion Research.
“More people are getting access to quantum computers than ever before, and I have a suspicion that they’ll do things with them that we could never even think of,” said Jamie Garcia at IBM.
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