From FLEET schools: Conductors, insulators and electricity
FLEET Schools: Light: reflection, refraction, diffraction
Digital technologies (anything with a computer chip) consume about 10% of global electricity and this proportion is increasing each year as we demand more and smarter, more powerful computing systems to be integrated into our daily lives. Taking a single photo on your phone requires about 1 trillion computations, which you then post on Facebook and send to friends – more computations, more energy.
Today, a lot of computer processing happens in huge factory-sized data centres. Some of the bigger data centres are more than 20 times bigger than the MCG (Australian football ground) and each use about the same amount of electricity as a large city suburb. Think Google, Facebook and Amazon, Microsoft. While scientists and engineers have developed ways to make these data centres extremely energy efficient compared to how your laptop or desktop computer stores and processes data, our increasing digital demands mean we continue to build more data centres and so our digital energy consumption continues to increase.
Facts to get you thinking The University of Cambridge Centre for Alternative Finance (CCAF) calculates that computational requirements of Bitcoin consumes somewhere between 40 and 445 terawatt hours (TWh) per year, with a central estimate of about 139 TWh, which is a bit more than the electricity consumption of Sweden. See other interesting CCAF comparisons here.
The International Energy Agency estimates that the growth in computational memory demands will outstrip global silicon supply by 2040. Silicon is the main material used in the memory storage devices – as well as the transistors that are the brains of your computers. (International Energy Agency. Digitalization and Energy 2017).
Internet traffic has tripled in the past five years. Calculations made in 2017 estimate that about 90% of the data in the world at that time was created in the previous two years. (International Energy Agency. Digitalization and Energy 2017). How would the same calculation done today compare?
No more for Moore
Moore’s Law (though it is not really a law) predicts that the number of transistors on a computer chip would double every 18-24 months, and it was right…until now.
For many years, the energy demands of an exponentially growing number of computations was kept in check by ever-more efficient, and ever-more compact silicon-based microchips. The microchips contain the transistors responsible for processing all your data. They are really the brains of the computer. We are, however, hitting the limit of physics with the conventional computer chip. We can’t make the transistors any smaller without breaking some laws of physics. This is another motivation behind FLEET’s research into the next generation of materials that will enable energy-efficient electronics and computation. Having said that, IBM claims it has produced the 2 nanometre chip – we are currently at the 5nm chip – but it is still a prototype and its efficacy is yet to be proven.
What is a nanometre? A nanometre is one billionth of a metre – or about 100,000 times thinner than a human hair. A single strand of DNA is about 2.5 nanometres in diameter. Today’s technology enables humans to manipulate single atoms and build stuff at the atomic level. Different atoms are different sizes, but an atom is about 0.5 nanometres or 1 million times thinner than a human hair. Researchers can pick up, manipulate and use atoms like Lego bricks to build novel materials and tiny new technologies.
What is FLEET doing
There are three broad technological approaches to a more sustainable digital future. FLEET has focused on the third approach.
- The development of renewable energy technologies.
- The construction of algorithms and use their use in artificial intelligence to help us use technologies more efficiently, for example detecting when an appliance is not in use and switching it off.
- Energy-efficient electronic technologies. This is where FLEET comes in. While climate change and environmental sustainability are integral to the problem FLEET is trying to solve, unless we develop a new generation of technologies that consumes less energy than today’s digital technologies, the future of computing could be choked by the lack of available energy in the next one to two decades.
Of course, we can also change human behaviour. A question for students to consider is what sort of world do we want to strive for, to live in? What are acceptable goals for technology development and how should they be used?
FLEET’s aim is to develop the next generation of low-energy electronics that will enable energy-efficient computing. A focus of FLEET’s research is the development of novel, atomically thin materials – materials that can be just one atom thick. These and other novel materials such as superfluids have the potential to conduct electricity without resistance, which means nearly all the energy is used for computing and none is wasted as heat. See below the section, Conductors, insulators and resistance. FLEET’s research will help reduce how much energy our technologies use and underpin the transition to technologies that use novel (non-digital) ways to compute.
A quantum solution
FLEET works in the quantum world, which is maybe where some of our deepest understanding yet of universe is. A focus of FLEET’s research is the development of novel and atomically thin 2D materials. FLEET researchers want to understand how these materials behave at the quantum level so they can manipulate and control their useful properties. They then need to be able to develop ways to fabricate these materials at a commercial scale.
For example, FLEET researchers are experimenting with different methods to force novel materials to temporarily become either topological insulators or shift to a superfluid state. They are also conducting research on exciton-polaritons, a weird quantum hybrid of light and matter.
Topological materials are new materials that are being investigated for their use in the next generation of transistors, even quantum computers. Topological insulators behave as electrical insulators in their interior, but can carry a current along their edges without resistance and therefore energy loss as heat. Resistance is where electrons interact with other particles in their journey through a circuit, in this case around a semi-conductor. Read more about topological insulators and topology here.
A superfluid is a quantum state. Whereas a superconductor can conduct electrical current flow without resistance, a superfluid has no charge, but can flow without resistance, meaning there is no friction that can impede its movement. But this superfluid state occurs only at massively cold temperatures (close to zero Kelvin or -273 degrees Celsius). FLEET conducting research into developing superfluids that operate at room temperature with the aim to integrate them into transistors. For senior physics students, check out some of FLEET’s research into superfluids
Exciton-Polaritons: Light and matter (anything made of atoms or the particles that make up an atom) are not supposed to mix. But scientists have now found a way to combine light and matter (electrons in this case) to make a new object called the exciton-polariton, whose weird quantum properties may enable us to develop electronic technologies that use a lot less energy, help build the quantum computer, detect black holes and stars colliding and build new types of low-energy lasers. Read more about these weird quantum particles here.
See the two videos below for further insight into FLEET research.