Topological Insulators: A Key to Quantum Tech
Everything’s made from something, and overall, most people feel like they’ve got a good understanding of which materials are used for what purposes. However, the smaller you get, the stranger things become, and things like topological insulators begin to become a reality.
In the hunt for materials to make better computers, everything’s getting smaller to reach quantum-level hardware. Some fresh approaches are being considered, but so is the use of existing ideas, such as conductors and insulators to manipulate everything going on within a system.
Hardware developers are beginning to see the end of their industrial reign as silicon gains are nearing their end, making way for newer materials. Materials that are either brand new, or existing materials that have been manipulated either by temperature, pressure, or a heavy magnetic charge.
Why the move from Silicon Insulators?
It’s simple. Silicon did its thing for a while, but now, we want less that does more. Silicon can only do so much in and of itself. Without some heavy manipulation, it is nearing the end of its usefulness as the demand for smaller yet more powerful hardware is in demand, and newer ideas are becoming a reality.
The Advent of Silicene
But silicon is not going down without a fight! Recently, a material has been produced out of silicon atoms, that is structured much like the new wonder material graphene. In this state, the material can be tuned via a magnetic field to become either a topological insulator or a band insulator. To dive deeper into silicene, check out this article from the New Journal of Physics.
Graphene- A Topological Insulator (Among Other Things)
One of the biggest threats to silicon is the advent and research into graphene. With the right treatment, layering, and twisting, you can get a conductor, a superconductor, an insulator, and a topological insulator from this quantum chicken wire! To learn a bit more about this material, check out this article about Twistronics.
Who Cares about Topological Insulators?
Who cares about topological insulators? That’s kind of like asking,
“Who cares about a cable internet service when you can use dial-up?”
“Why use a turbine engine if you can get from point “a” to point “b” using a prop?”
Topological insulators offer a host of solutions in the realm of quantum computer hardware that standard materials used in circuity don’t provide- or at least, don’t provide as well.
Getting things smaller, more powerful, more reliable, faster, and more energy conscious are some of the checkboxes that topological insulating materials are meant to tick. The targets being shot at are numerous in terms of benefits.
Smaller circuitry, harnesses, or hardware, are the tip of the iceberg. In time, this technology will overtake how things are done today, just as digital overtook analog in the early 2000s.
Energy Conscious Technology
Saving energy is a big deal right now, while the world uses all kinds of energy to scream “conservation” to the heavens. Well, one of the best ways to conserve energy is to not use it in the first place, which happens to be a byproduct of using superconductors, or in other words, zero resistance conductors.
Going Small- Running Cool
These days, data runs hot! It runs so hotly that cooling circuitry down has become an industry in itself. Everything from PC fans to liquid-cooled systems, to refrigeration cooling systems, are hard at work keeping our motherboards from burning out.
Average cooling infrastructures account for about (50%) of the energy consumption of a typical data center. In comparison, data storage and servers consume a combined 26%. (Nature.com)
If you eliminate the bulk of the cooling apparatus, the energy efficiency of a system skyrockets- not that the 50% energy savings wouldn’t be replaced with more data storage demand, server tech, and overall computing stuff, but it’s a fine notion.
The point is, topological insulators’ outer edges have zero resistance to the flow being carried around them. No resistance, no energy generating into heat, resulting in less energy usage.
One idea is to make a new type of transistor.
Using a topological insulator in a transistor would replace the gate between the source and drain. Generating less heat and using less energy than silicon-based counterparts will solve energy issues that come with massive computing and is projected to be a concept used among the first quantum computers, paving the way for dissipationless information transmission.
For the sake of summing it up, newer transistors will be much smaller, they’ll work better, run faster, and keep cooler.
Making A Topological Insulator
In the infancy of this discovery, the following is the method used to create the topological insulator. In a way, it was discovered by accident.
Researchers ran high magnetic fields through a thin film of material (2-dimensional Galvene) to create a variety of different energy bands with gaps between them- originally thought to create an insulator until it came time to run some tests.
When the research commenced, the results were unexpected. Rather than an infinite range of resistance, they found that resistance levels were dropping down to zero. The material winding up as a perfect conductor offering zero resistance didn’t make much sense until physicists took a closer look at what was going on.
Quantum Hall Effect
The electrons lined up within the interior of the surface of the 2D material are held firm as an insulator (as was supposed by researchers before testing). However, electrons traveling around the outer edge without any form of resistance is what was foiling initial studies.
This discovery observed electrons traveling in a circular motion, “chasing its tail” so to speak while moving along the outer edge of the material in only one direction. This discovery is what deemed the material to be called a “Topological Insulator.” The internal geometry of the film works as an insulator, while the outer edge works as a superconductor.
This was recognized in 1985 and was called the “Quantum Hall Effect.”
Since then, physicists have understood that there are a lot of materials out there that carry this property without having to create a high magnetic field to generate the result. It was just not yet discovered until more recently. The key to making these materials topological insulators is to make the material extraordinarily thin.
Though the materials can be stacked to reap different or compounding results, they’re still only a few atoms thick. Research carries on to reveal more of what to expect in the real-world usage of topological insulators, and the overall process while considering material production.
