'World's purest silicon' could lead to 1st million-qubit quantum computing chips

Scientists have created an enhanced, ultra-pure form of silicon that could one day be the foundation for highly reliable "silicon-spin qubits" in powerful quantum computers.

While the bits in classical computers encode data as either 1 or 0, qubits in quantum computers can be a superposition of these two states — meaning they can achieve a quantum state known as "coherence" and occupy both 1 and 0 in parallel while processing calculations. 

These machines could potentially be more powerful than the world's fastest supercomputers but would need around a million qubits to achieve this, the scientists said. The largest quantum computer today has roughly 1,000 qubits. 

But a key challenge with quantum computing is that qubits are "noisy," meaning they are highly prone to interference, such as temperature changes, and need to be cooled to near absolute zero. Otherwise, they easily lose information and fail midway through operations. 

This means that even if we had a quantum computer with millions of qubits, many of those would be redundant even with error-correction technologies, making the machine extremely inefficient.

Tapping into silicon quantum computing

Qubits are normally made from superconducting metals such as tantalum and niobium because they possess near-infinite conductivity and near-infinite resistance.

But in a new study, published May 7 in the journal Nature Communications Materials, researchers proposed using a new, pure form of silicon — the semiconductor material used in conventional computers — as the basis for a qubit that is far more scalable than existing technologies.