Ray O. Johnson, left, board member of quantum computing start-up QxBranch and the former senior vice president and chief technology officer of defense giant Lockheed Martin, and Michael Brett, QxBranch’s chief executive. (Jeffrey MacMillan/For The Washington Post)

Imagine a computer that could sift through millions of financial transactions in real time to detect fraud or look for signs of insider trading, and do it exponentially faster than the most powerful computers in the world today.

A Washington start-up is betting that such a machine can be built in the not-too-distant future, using the mysterious principles of quantum computing.

QxBranch (pronounced ­Q-Branch) is the latest project by Michael Brett, an Australian entrepreneur whose previous venture, Aerospace Concepts, teamed up with Lockheed Martin last year to explore the futuristic realm of super-fast quantum computers.

QxBranch — a spinoff from Aerospace Concepts — was born out of that collaboration and develops and tests commercial applications for quantum computing. The company has Lockheed’s recently retired chief technology officer, Ray Johnson, on its board of directors.

The power of quantum computing lies in its ability to perform complex calculations much faster than traditional computing systems, Johnson said. It could help large organizations solve logistics and optimization problems or enhance machine learning used in artificial intelligence systems, he said.

"If you think you understand quantum mechanics, you don't understand quantum mechanics," said the late Nobel laureate Richard Feynman, widely regarded as the pioneer in quantum computing. The science video blog Vertiasium tries to help make sense of it.

At Lockheed, Johnson led the defense giant’s foray into quantum computing. The contractor and the University of Southern California jointly own one of two commercially available quantum computers in the world, manufactured by Canadian firm ­D-Wave (The other one is owned by Google and NASA). Lockheed also established a quantum computing research center at the University of Maryland’s College Park campus last year.

For now, a machine that can solve such large-scale problems exists only in theory. That’s because quantum computers are highly unstable, delicate systems that can function only in protected environments to eliminate interference from other particles. They are usually kept in supercooled environments colder than outer space.

There are additional uncertainties. For example, quantum computers are known to be useful for certain types of calculations such as codebreaking, but for others, such as machine learning and optimization, scientists still don’t know for sure whether they will outperform a classical system, said Scott Aaronson, an associate professor of electrical engineering and computer science at the Massachusetts Institute of Technology.

Recent experimental progress has given some in the field hope that scalable quantum devices are within reach, he said.

Last week, IBM published a research paper describing two developments that could have significant implications for the future design of such computers. IBM’s research was funded in part by the Intelligence Advanced Research Projects Activity, which has sponsored several such efforts in the past.

The team demonstrated a way to identify and detect arbitrary errors in a quantum computer simultaneously; until now, only one type of error could be detected at a time. They also showed that it was possible to detect errors on a design that could potentially be scaled up to create larger, more powerful quantum computers.

For IBM, one commercial application of quantum computing lies in biochemistry. Theoretically, scientists could simulate natural molecules to gain a better understanding of their underlying chemistry by using quantum computing, said Jerry Chow, manager of IBM’s experimental quantum computing group. That could have the potential to improve drug design, he said.

The research findings are a very important step forward, but scientists still have a long way to go toward building a stable and scalable system, said Daniel Lidar, a professor of electrical engineering and chemistry and the scientific director of the USC Lockheed Martin Quantum Computation Center.

The advantage of a quantum computer over a classical computer lies in the way it performs big calculations. Traditional computers use bits — 0s and 1s — to perform calculations in a sequential manner. Quantum computers, on the other hand, use devices called “qubits” that can simultaneously exist as both 0s and 1s. Using this property, quantum computers can theoretically cut down the number of calculations required to solve a problem, quickly providing a potential solution or a set of probable solutions to a problem.

This property is key to solving highly specialized problems such as codebreaking or crunching big data more efficiently than a classical computer.

That’s why quantum computing has long attracted the interest of government agencies including the National Security Agency, which had plans to design its own computer to break encryption, and the National Institute of Standards and Technology, which has a request for information out on the potential uses of quantum computing.

At QxBranch, Brett says he is confident that advances in quantum computing design are already paving the way for commercial applications. The company, which has four employees in Washington and 15 around the world, has raised capital from angel investors that it will spend to validate uses of quantum computing. A Series A financing round should follow at the end of the year, Brett said.

Correction: An earlier photo caption with this report incorrectly stated that Michael Brett was a former senior vice president and chief technology officer at Lockheed Martin. Ray Johnson was the former Lockheed Martin executive.