New Caltech study shows it’s possible to build 1k logical qubits with only 10k physical qubits

A new study by Caltech and neutral atom quantum computing company Oratomic has revealed that a fully realized quantum computer could be built with as few as 10,000 to 20,000 qubits, as opposed to previous estimates of millions of qubits. This can be achieved using a new quantum error-correction architecture for neutral atom computers, proposed in the study, that is significantly more efficient than previous approaches. Key to this, said the announcement, is the neutral atom modality’s dynamic ability to move atoms; laser beams, known as optical tweezers, can be used to arrange atoms into qubit arrays.

“Unlike other quantum computing platforms, neutral atom qubits can be directly connected over large distances,” Endres says. “Optical tweezers can shuttle one atom to the other end of the array and directly entangle it with another atom.”

In other error-correction schemes, such as those using so-called surface codes, qubits arranged in two dimensions are limited to connections to their direct neighbors. In neutral atom arrays, the qubits can be connected to many other qubits that are far away, enabling what scientists call high-rate codes. In such protocols, each physical qubit can participate in many logical qubits instead of just one. This means that each logical qubit could be encoded with as few as five or so physical qubits, as opposed to the 1,000 needed with other techniques. This thereby deceases the number of physical qubits needed to produce 1,000 logical qubits – the number typically cited as being the threshold needed to execute Shor’s algorithm.

The accelerated timeline indicates that the security of digital communications—which includes everyday financial transactions and many other forms of private messaging—could be vulnerable to data breaches sooner than expected.

Read the study here.