Quantum Computing: The Hype and the Reality

A heated discussion is happening in the world of quantum computing. On March 18th, Chetan Nayak, a physicist leading Microsoft’s quantum team, shared new details about the company’s quantum computing chip. This was done at the American Physical Society’s Global Physics Summit in Anaheim, California. It was an attempt to settle a big debate among physicists. But, many researchers are still not convinced by the results. The main issue is Microsoft’s claim from February. They said they had made a new type of quantum hardware. This hardware is called a topological qubit. It is made from a pattern of electrons on a tiny wire. Microsoft said this qubit makes fewer mistakes. This could make quantum computers easier to scale up. But, the editors of the journal where Microsoft published their findings were not fully convinced. They said Microsoft had not clearly shown the electrons forming the expected pattern. This is not the first time Microsoft has had to backtrack on similar claims. In 2021, they had to retract a similar statement. The excitement around quantum computing is real. Champions of this technology say it will change materials science, encryption, and finance. They believe quantum computers could one day do certain tasks much faster than regular computers. But, the timeline for this is unclear. In January, Nvidia’s Jensen Huang said he doubted that commercial quantum computing would exist in 15 years. This caused quantum computing stocks to fall. He later tried to clarify his comments, but the stocks fell again. Despite the controversy, researchers are making progress. Over the past few months, companies like Google, Amazon, and several startups have announced improvements in quantum computing. But, it’s hard to say how much longer we’ll have to wait for quantum computing’s big breakthroughs. Will quantum computers be in your cloud or phone in the future? And who are they really for? Quantum computers work differently than regular computers. They use something called superposition. This is a concept from quantum mechanics. It’s like a coin flipping in the air. Before it lands, it’s neither heads nor tails, but both. Similarly, a qubit can represent information as some probability of both one and zero. This is different from a regular computer, which encodes information as binary ones and zeros. Researchers are using different materials to make physical qubits. For Google, Amazon, and IBM, each qubit is a small superconducting circuit. Some startups are using ions, atoms, and photons as qubits. It’s not clear yet which material is best. One of the early useful applications of quantum computers could be performing accurate and fast chemistry simulations. This could help discover new materials for better batteries, more climate-friendly fertilizers, and new medical drugs. Currently, scientists rely on supercomputers for these simulations, which are inexact and slow.

Quantum computers could also upend other industries. Banks are looking into quantum optimization algorithms for better financial forecasts. Quantum algorithms could make AI algorithms more energy-efficient. They could also break existing encryption methods, which has sparked research into more robust forms of cryptography. But first, researchers need to reduce the errors in quantum computers and make them larger. When they do become useful, ordinary consumers shouldn’t expect them as personal devices. Experts envision future quantum computers as a specialized chip in a supercomputer or as a data center. Users would access the machine through the cloud. It’s also unlikely that quantum computers will be useful for everyday tasks like word processing or internet browsing. Their proposed applications are largely specialized for technical fields such as pharmaceuticals and finance. Recent progress has been encouraging. The first quantum computers of note, built in the last decade, were too error-ridden to execute useful algorithms. Lately, researchers have figured out how to correct computing errors by encoding a single unit of information in multiple physical qubits instead of one. Using this approach, Google and Amazon have shown that their quantum computers can more reliably store information without the machines becoming more error-prone as they get bigger. The results could pave the way toward larger, useful quantum computers. Still, a leap for physicists is an inch forward for the rest of us. Google and Amazon’s quantum “memory” only stored a single unit of quantum information, known as a logical qubit. A useful quantum computer will need thousands, perhaps a million physical qubits, corresponding to hundreds or thousands of logical qubits. Researchers need to reduce the number of physical qubits to encode a unit of information. In Amazon’s recent announcement, they only needed nine physical qubits per unit of information, compared to the 105 physical qubits that Google needed. “We are a long way away from the big, mind-blowing, world-changing results and applications, ” says Morello. Governments and private investors are pouring money into quantum computing. The US, European Union, and the UK governments have each pledged funding in the billions. The US sees China as its main rival, which has poured $15 billion of public funding into quantum computing. In the private sector, Crunchbase reported that quantum computing received $1. 5 billion in venture funding worldwide in 2024, an all-time high. But building the technology is difficult. Researchers have to show progress to keep their investors happy, while also tempering their expectations to keep them patient. The worry is a potential “quantum winter, ” where overhype leads to inflated expectations and disappointment, and investors withdraw funding.

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