Scientists have made a massive breakthrough towards a scalable quantum computer.

Researchers from the University of New South Wales (UNSW) came up with a compact sensor which can access information from the electrons of individual atoms. Michelle Simmons led this research at the Center of Excellence for Quantum Computation and Communication Technology (CQC2T) and it was published in the journal ‘Physical Review X (PRX). This is quite an important development because it brings humanity a step closer to scalable quantum computing in silicon.

The efforts of the team of Simmons is acknowledged globally as they are considered the world-leaders when it comes to creating ‘Quantum Bits (Qubits). These special bits are produced by using electrons hosted on single atoms in semiconductors. This method is probably the most promising one for developing large-scale quantum computers due to the long-lasting stability of these elements. In this technique, individual phosphorus atoms are precisely positioned and encapsulated into a silicon chip.

The addition of all the gates and connections (needed to scale up this architecture) has always been a challenging task for the scientists but things may change drastically with this latest research. Simmons talked about that in the following words:

“To monitor even one qubit, you have to build multiple connections and gates around individual atoms, where there is not a lot of room. What’s more, you need high-quality qubits in close proximity so they can talk to each other — which is only achievable if you’ve got as little gate infrastructure around them as possible.”

It is clearly evident from this explanation that the gate density needs to be minimized as much as possible. In comparison to other methods for making a quantum computer, the system used by Simmons’ team was already using a low gate density. However, that approach still needed at least 4 gates per qubit (3 to read and 1 for control). The integration of the new read-out sensor into one of the read gates reduces this number to just 2 gates per qubit (1 to read and 1 for control). Prasanna Pakkiam, a Ph.D. student at the UNSW, described that by saying,

“Not only is our system more compact, but by integrating a superconducting circuit attached to the gate we now have the sensitivity to determine the quantum state of the qubit by measuring whether an electron moves between two neighboring atoms. And we’ve shown that we can do this real-time with just one measurement — single shot — without the need to repeat the experiment and average the outcomes.”

The first Australian quantum computing company, Silicon Quantum Computing Pty Limited (SQC), began its operation in May 2017. Since then, they have been trying to create and commercialize a quantum computer by making use of the technology developed at the CQC2T. Similarly, SQC is also located on the UNSW Campus in Sydney. The researchers of this forum are working on a handful of parallel technology developmental projects. Their primary objective is to demonstrate a 10-qubit device in Silicon by 2022, which will act as a forerunner to a commercial scale silicon-based quantum computer.

This organization was initiated by a unique coalition of governments, universities, and corporations. Consequently, it is competing with some of the largest foreign research laboratories and tech multinationals of the world. In addition to their own proprietary technology, SQC is also collaborating with CQC2T and some other participants of the Australian and International Quantum Computing Ecosystems. The basic aim of this collaboration is to build a quantum computing industry in Australia and then spread it to other parts of the world.

SQC believes that quantum computing will have applications in various fields of our lives including machine learning, financial analysis, rapid drug design and testing, stock market modeling, early disease detection and prevention, and software design. In addition to the social benefits of these applications, they will also help in boosting the global economy. Simmons, one of the world-leading quantum researchers, concluded the matter by discussing the importance of this advancement. He said,

“This represents a major advance in how we read information embedded in our qubits. The result confirms that single-gate reading of qubits is now reaching the sensitivity needed to perform the necessary quantum error correction for a scalable quantum computer.”