Science

Quantum Computers: Milestone Reached with Perfectly-Placed Atoms

Talk about a quantum leap.

Australian researchers made a quantum leap in leading the push towards creating a fully functional quantum computer.

Michelle Simmons and her team at the University of New South Wales were able to make three precisely placed atoms inside a silicon chip communicate information between each other. This is precisely the type of architecture that will be needed to build quantum computers out of silicon — a material that is used for pretty much every consumer electronic on the market.

The paper detailing this study was published in the journal Nature Communications, and marks a major milestone on the long journey towards the holy grail of modern-day computing.

What makes quantum computing systems so great is how they store data.

The computers we use today store information in what is known as a bit, which must be either a one or a zero. Quantum systems use “qubits,” which can represent one and zero at the same time. This seemingly minuscule change allows these computers to plow through calculations at speeds that are completely impossible to achieve even with today’s supercomputers.

A scanning tunnelling microscope image showing the electron wave function of a qubit made from a phosphorus atom precisely positioned in silicon.

UNSW

Qubits can be made from any kind of atomic particles, but are notoriously difficult to track. Simmons’ team is the only group in the world that has the ability to see the exact position of their qubits.

“In placing our phosphorus atoms in the silicon to make a qubit, we have demonstrated that we can use a scanning probe to directly measure the atom’s wave function, which tells us its exact physical location in the chip,” she said in a statement.

Simmons’ study also found that placing these atoms exactly 16 nanometers apart in the chip allowed them to relay information back and forth, which resulted in the qubits moving in reaction to one another. This is a phenomenon known as quantum entanglement — or when qubits interact in a highly correlated manner.

“It was fascinating to watch. When the spin of one electron is pointing up, the other points down, and vice versa,” said Matthew Broome, the lead co-author of the study. “This is a major milestone for the technology. These type of spin correlations are the precursor to the entangled states that are necessary for a quantum computer to function and carry out complex calculations.”

Getting a large array of qubits to function as one cohesive unit is the end goal. Once a certain number of these particles are able to work together, they are capable of solving pretty much any computational problem out there. But knowing qubits and their quantum weirdness, this will be no easy task.

This study has essentially laid out the foundation of how a quantum computer could be built using common materials. If researchers are able to place more qubits in a chip and see the same results as in this study, a new age of computing might be on the horizon.