31 August 2023
By Emma Hankins
Quantum technologies have recently been predicted to revolutionise computing, hack the entire internet, and even save the planet. People seem to be throwing the word ‘quantum’ in front of just about anything: computers, sensors, even a Marvel film.
If you’ve found yourself asking, ‘What even is quantum? And why should I care?’, you’re not alone. I have never taken a single physics (or even high-level maths) course, and frankly, I’d rather keep it that way. So when I recently took on a project researching enablers for quantum tech research, development, and commercial expansion, I feared I was way out of my depth. But as all policymakers should know, you don’t have to know every minute detail of a topic to understand its importance.
My goal is that by the end of this post, you will absolutely not be an expert in quantum tech. Instead, my hope is that you will have a clue what people are saying when they talk about quantum, and you’ll understand why it’s important to policymakers.
When people refer to quantum technologies, such as quantum computing, quantum sensing, quantum imaging, or quantum cryptography, they are typically referring to science that applies quantum mechanics to a given field of technology.
You may have heard the phrase quantum mechanics before. If that phrase makes total sense to you and explains quantum tech entirely, please feel free to move along. This blog is for everyone else.
As the Defence Science and Technology Laboratory’s excellent biscuit book puts it, ‘Quantum mechanics is the mathematics that describes and predicts the behaviour (actions and interactions) of atoms and the sub-atomic particles inside them.’ In other words, quantum mechanics is maths applied to very, very small particles.
Why do we need a whole other field of mathematics to understand the behaviour of very small particles? Simply put, because very small particles don’t always follow the same rules of physics as larger objects (the rules most of us are more familiar with and see every day). For example:
Here’s the mantra I found myself repeating whenever I got lost: quantum mechanics means things behave weirdly. And as we’ll see, we may be able to turn those weird behaviours to our advantage in order to solve problems.
The area of quantum technology that gets the most attention (some would say hype) and funding is computing. A quantum computer seeks to harness the unusual characteristics of quantum mechanics to solve computational problems.
In classical (that is, non-quantum or ‘normal’) computing, we use binary code or ‘bits’ representing 1 or 0. Quantum computing, however, uses ‘qubits’, which can represent 1, 0, or both at the same time. This is due to superposition, one of the weird behaviours mentioned above.
Quantum computing is still a relatively young and quickly changing field. There are a number of different ways that researchers are currently trying to develop these all-important qubits, and it’s not yet clear which technology will work best. It may even be that certain technologies work best for certain types of computation. It is critical to keep this inherent uncertainty in mind when considering the hype around quantum computing.
While quantum computing gets the most attention, products from other areas of quantum tech are actually closer to market and, in some cases, already in use.
Quantum sensors are one such group of products. This includes quantum gravity sensors or gravimeters, which measure the effects of gravity on quantum particles. These highly sensitive instruments can sense underground structures, meaning their use can avoid manual and invasive surveying work ahead of building new infrastructure, for example.
Similarly, the field of quantum imaging uses the weird quantum behaviours of photons, the subatomic particles of light, to help humans see everything from a speeding car around a corner to dangerous leaks of gases invisible to the human eye.
Timing is another well-established area of quantum tech. While most of us are content with ordinary clocks, powered by quartz crystal oscillators, to keep us on time in our daily lives, these clocks are actually considered fairly unreliable by scientists, who may need clocks that are consistently accurate to the nanosecond. To get this level of accuracy, scientists use atomic clocks, which combine quartz crystal oscillators with specific atoms. To oversimplify it, these clocks blast an atom with a specific frequency of microwaves until the atom starts to shake or oscillate. How fast a particular atom oscillates in response to that microwave is the same across all atoms of that element in the entire universe, providing scientists with a much more accurate measure of time. It’s this accurate measurement that enables many technologies that rely on satellites, such as GPS. And quantum timing tech is now moving beyond atomic clocks, with scientists developing quantum logic clocks and optical clocks.
Perhaps the most obvious policy concern raised by quantum technologies is around cryptography. Today, much of our data is encrypted based on equations designed to take classical computers many years to perform. This keeps the data safe from hacking because performing those computations is simply unworkable for computers today.
However, using the unusual properties of qubits, quantum computers may be able to quickly hack such encrypted data. While such computers would still be extremely expensive and may be years or decades away from deployment, such a threat of large-scale decryption is certainly something for policymakers to consider. Some countries are already taking precautions, with the US government announcing in 2022 that federal agencies should prepare to shift to new quantum-resistant algorithms. On the other hand, some countries appear to be collecting currently encrypted data in the hopes of being able to decrypt it once a powerful enough quantum computer has been built.
While the potential implications of such a powerful quantum computer are terrifying, quantum scientists have developed the field of quantum cryptography to address this issue. One technology in this field, quantum key distribution, takes advantage of entanglement to send communications using quantum states that are altered if observed by an unauthorised third party. In this way, people sending the communications would be automatically alerted of any ‘eavesdroppers’. However, quantum key distribution is still a developing technology and cybersecurity agencies in the US and UK do not currently recommend it, focusing instead on ‘quantum-safe’ algorithms to protect against future threats from quantum computers.
In terms of its transformative potential across fields, I’ve heard experts compare quantum tech to things like the internet and AI. It can be hard to untangle the truth from the hype with such a complex and rapidly evolving area of science. However, there is certainly a possibility that quantum tech may be the next technology to fundamentally change the way we work in every field from drug development to natural resource extraction. It is therefore critical that policymakers are aware of quantum tech and ready to respond to its rapid advances — or, better yet, be proactive about supporting and regulating these new technologies.