Quantum Motion on Thursday said it raised $160 million to fund its effort to build a quantum computer that is smaller, cheaper, and more ​energy efficient than rivals using standard silicon chipmaking techniques.

Quantum computers hold the promise of solving problems that regular computers cannot. At the heart of that ability is what is known as a qubit.

Unlike the transistors in an everyday computer that can only represent a zero or ​a one at any given time, a qubit can represent both at once. ​There are a variety of ways to make qubits, such as using superconductors like those used by IBM or Alphabet's Google, or by hitting neutral atoms with lasers.

The challenge with each of them is scaling up to the thousands or millions of qubits needed to make a working quantum computer. London-based Quantum Motion took a different approach: Take something easy to make in the millions, such as the transistors used in phone and laptop chips, and figure out how to make qubits from them.

"We just kind of started the company in ​reverse," said James Palles-Dimmock, Quantum Motion's CEO. "What are the minimum adaptations that we can make to transistors ‌to turn them into high-quality qubits?"

In a classical computing chip, a transistor is either on or off, and electrons flow across a gap when the transistor is on. Quantum Motion suspends a single electron in the gap and manipulates it with a magnetic field.

This so-called electron spin ​concept is not entirely ​new; several other startups, as well as Intel, are using it. Quantum Motion believes it has found a way to make it work in practice ​with chips made by its manufacturing partner, GlobalFoundries. Palles-Dimmock said this could ​allow Quantum Motion to make useful quantum computers for as little as $10 million to $20 million.

"We've got a very clear path to delivering the world's most powerful computer at a reasonable cost," Palles-Dimmock said.

The funding round ​was co-led by DCVC and Kembara, with participation from ​British Business Bank and Firgun. Also joining the round were existing investors Oxford Science Enterprises, Inkef, Bosch Ventures, Porsche ​Automobil Holding and Parkwalk Advisors.