Blog Post Two - A New Breakthrough for Silicon in Quantum Computing

You may recall last week that I posted an introductory video to help explain quantum computing. In the introductory video, Andrea Morello, a researcher at the University of New South Wales, gave a very clear introduction to the very complex topic of quantum computing. As it turns out, as of just yesterday, Morello and his research team have just discovered a new breakthrough in quantum computing! I was excited to discover that Morello, a researcher I did not know about until last week, had literally just made a new discovery!

Picture of Andrea Morello, Photo Credit: Marcus Eno

The news article was published in Cosmos Magazine (Not to be confused with Cosmo!).

Here is a link to the article which published Morello's breakthrough:

https://cosmosmagazine.com/technology/breakthrough-quantum-computers

You will recall from my last post a brief discussion of the quantum bit (Qubit), and that it has the ability to maintain the state of 1 and 0 at the same time, creating a super-position. The qubits bits have been made out of a variety of elements that researchers have been testing. Morello and his research team have been trying to use the properties of silicon, by taking a single phosphorus atom entombed in a silicon crystal. If we were able to change the state of silicon qubits using only a single electrical charge/pulse, it would significantly lower the current cost of manufacturing these quantum machines in addition to opening an entirely new array of possibilities.

In order to read the super-position states of the quantum bits, Morello uses magnetic field generators, which according to the article, cost "around $100,000 a pop" (O'Connell 2015). The article continues to explain that "If they had to use one for each quantum bit in a large array, the cost would be astronomical. There is also a practical problem. Magnetic fields spread, making it impossible to control one quantum bit in an array without inadvertently affecting all its neighbours" (O'Connell 2015).

The breakthrough Morello's team and an experimental physicist named Arne Laucht discovered is that they found a way to control each quantum bit using a simple electrical pulse, as opposed to using a magnetic field generated to control each quantum bit. This is significantly more practical and opens up so many more doors for these silicon quantum computers. "Instead of each phosphorus atom having a dedicated magnetic field generator to control it, their new design floods the whole device with a single magnetic field" (O'Connell 2015). It was also mentioned that if the electrical pulses were timed properly, it could avoid the problem of unwanted affecting of neighboring qubits.

Essentially, this breakthrough will significantly reduce the cost of quantum computers in addition to improving their accuracy. The cost is improved due to needing fewer magnetic field generators to control qubit positions, and the accuracy is improved due to neighboring fields not confusing eachother's super-positions via alteration of magnetic polarities. I wish Morello and his team the best of luck in their future research and hope to hear about more advancements to silicon quantum computers in the near future!

Reference:

C O'Connell. (2015). Breakthrough for quantum computers. Cosmos Magazine