After several dashed predictions, quantum computing is accelerating rapidly with actual use cases and scientific breakthroughs expected within years, not decades.

US tech giants, startups, banks and pharmaceutical companies are pouring investments into this revolutionary technology.

Here's what to know about tech that may change the world, but can be hard to decipher:

- Beyond 0 and 1 -

While classical computing relies on bits with just two states (0 or 1), quantum computing harnesses "qubits" with infinite possible states.

Each added qubit theoretically doubles computing capacity, allowing quantum computers to analyze countless possibilities simultaneously, solving in minutes what might take millions of years classically.

"Classical computers are speaking the wrong language. In quantum we're almost speaking the language of nature," said John Levy, CEO of hybrid chip developer SEEQC. "This unlocks previously unsolvable problems."

Microsoft recently unveiled quantum technology based on an entirely new state of matter -- neither solid, gas, nor liquid.

Levy's verdict: "They should win a Nobel Prize."

- 'Efficiency race' -

Given its exponential computing power, Levy believes quantum's potential exceeds our "limited imagination," especially when paired with AI.

Some even view quantum computing as the only path to "superintelligent" AI with superior cognitive abilities.

Practically speaking, quantum technology will dramatically accelerate discovery of new molecules -- extending the periodic table learned at school.

This will mean new materials, breakthrough medications, advanced fabrics, complex financial models, and super-efficient batteries.

Philosopher and investor Anders Indset foresees an "efficiency race" transforming everything from agriculture to transportation: "We'll have hyper-efficient, lighter cars and cheaper, cleaner air travel methods."

- Too much noise -

Quantum computers already operate today.

IBM claims its quantum services have generated sales of $1 billion, though current applications remain limited mainly to research.

The market will initially expand through servers equipped with specialized chips and systems.

"We are now switching from quantum theory to the quantum economy," said Indset.

This explains why cloud leaders Amazon, Microsoft, and Google are jumping in.

"The drive is to be leader in trillion dollar industries," Indset added.

The giants, already in a furious race to lead on AI, are heavily investing to solve quantum's biggest challenge: calculation errors.

Qubits require sub-freezing temperatures and are extremely sensitive to environmental "noise" - vibrations, heat, electromagnetic interference - that cause computational errors.

Google's new Willow quantum chip and Amazon's Ocelot semiconductor prototype aim to dramatically reduce these errors and costs.

"We're witnessing the creation of an ecosystem," said Levy, the CEO, noting that pharmaceutical giant Merck is investing in SEEQC to secure access to future quantum tools.

- Is it safe? -

The US and China are racing ahead in quantum development, with Washington imposing export restrictions on the technology.

Beyond competition, quantum computing poses serious cybersecurity concerns.

Since qubits can test countless combinations simultaneously, they could potentially break conventional encryption methods.

US government agencies and tech companies like Apple are already developing "post-quantum" encryption to prepare for this new reality.

AFP

Microsoft says the chip will help build meaningful quantum computers in years. Photo by MICROSOFT

Quantum leap: computing's next frontier takes form