How Graphene is Hastening the Rise of Quantum Computing

How Graphene is Hastening the Rise of Quantum Computing

Quantum computing has long been regarded as the next “big thing.” Now it’s looming ever larger on the horizon, and graphene is part of the reason for that.

Dr. Rajamani Vijayaraghavan, head of the Quantum Measurement and Control Laboratory at the Tata Institute of Fundamental Research (TIFR), told Swarajya Magazine in September 2020 that an everyday quantum computer — i.e., one “that is practical and commercial in nature,” as he put it — is still a “couple of years” down the road.

But there have been strides in that direction for several years, and experts relish all that these computers might have to offer. So grand is their processing power, in fact, that it is believed they will be able to meet some of the world’s greatest challenges in a fraction of the time it takes classical computers. They can hasten the development of environmentally friendly technology, for instance. They can shorten the timeline for the development of drugs and vaccines. They can make market forecasting more sophisticated and supply chains more efficient.

The caveat is that the quantum bit (i.e., the qubit), the basic building block of quantum computers, is notoriously sensitive to its environment. In fact, until last year they always had to be supercooled at minus-272 degrees C (1 kelvin). They simply could not operate at higher temperatures.

This is one of the places graphene could come into play. Researchers, already aware of the substance’s superconductivity, discovered in 2020 that graphene was the first material capable of serving simultaneously as a superconductor, insulator and ferromagnet. That resulted in the further revelation, in February 2021, that when three layers of graphene were twisted — one more layer than had previously been attempted — the material’s conductivity was enhanced to the point that scientists could envision them operating at room temperature. 

Also in February 2021 came a further development in the field of valleytronics, which seeks to exploit a property in graphene known as “the valley,” which is not unlike the spin of electrons in other materials. This new method again involves twisting layers of graphene — this time two, instead of three — after they are placed between a ferromagnetic insulator. It is expected that this method will increase processing speeds.

A few months earlier, in October 2020, scientists discovered that a bolometer, a device that detects the tiniest of energy changes in quantum computers — changes that can negatively impact qubits — operated far more quickly and efficiently when it was made of graphene as opposed to gold palladium alloy, as had previously been the case. 

Taken together, these developments indicate that we are drawing ever nearer to seeing quantum computers become a reality. While experts caution that there are “many, many hurdles yet to overcome,” these are promising strides in the right direction.