There's a New Quantum Computing Record: Control of a 6-Qubit Processor in Silicon

 

On the path to fully functional and capable quantum computers, another milestone has been reached: full control of a 6-qubit quantum processor in silicon.

It's "a big stepping stone" for the technology, according to researchers.

The quantum version of classical computing bits, qubits (or quantum bits) have the ability to process far more data than their classical counterparts. They can be in two states simultaneously rather than simply a single 1 or 0, according to quantum physics.

This jump to six is crucial because the challenge is getting many qubits to behave as we need them to. The method may be more practical if it can operate in silicon, the same material utilised in modern electronic devices.

According to quantum computing expert Stephan Philips of the Delft University of Technology in the Netherlands, "the quantum computing issue today consists of two aspects." "Creating qubits of sufficient quality and an architecture that enables the construction of massive qubit systems."

"Our work is appropriate for both groups. And given that creating a quantum computer is a massive undertaking, I believe it is fair to conclude that our contribution has gone in the correct direction."

Individual electrons are set in a row, 90 nanometers apart, to form the qubits (a human hair is around 75,000 nanometers in diameter). This line of "quantum dots" is embedded in silicon using a transistor-like structure. The team was able to successfully regulate the spin of the electrons, the quantum mechanical feature that permits the qubit state, by making meticulous adjustments to how the electrons were created, controlled, and monitored.

Additionally, with little mistake, the researchers were able to build logic gates and entangle systems of two or three electrons.

Researchers operated electron spin as qubits and got them to interact with each other as needed by using microwave radiation, magnetic fields, and electric potentials.

According to electrical engineer Lieven Vandersypen, also from the Delft University of Technology, "In this research, we push the envelope of the number of qubits in silicon and achieve high initialization fidelities, high readout fidelities, high single-qubit gate fidelities, and high two-qubit state fidelities."

What is really noteworthy, though, is that we show all three qualities in one experiment using a record number of qubits.

We're talking about a significant advancement in terms of what's achievable in this type of qubit because, up until now, only 3-qubit processors have been effectively manufactured in silicon and managed up to the requisite degree of quality.

There are several ways to construct qubits, including on superconductors, where many more qubits have been operated in tandem, and researchers are still trying to determine which approach could be the most advantageous going forward.

The advantage of silicon is that the supply and production networks are fully established, thus the transfer from a laboratory to an actual machine ought to be simpler. The qubit record is being pushed higher and higher by ongoing work.

According to electrical engineer Mateusz Madzik from the Delft University of Technology, it is conceivable to raise the silicon spin qubit count while maintaining the same precision as for single qubits with careful engineering.

"In the subsequent generations of research, the key building block established in this work could be used to add even more qubits."or found in common processors.

Reference:  Nature.