What is quantum, anyway?

At its simplest, quantum mechanics is the field of physics that tries to explain the behaviour of matter and energy at the smallest scales - atoms and subatomic particles. These particles don’t follow the predictable rules of classical physics but instead can exist in multiple states at once, a phenomenon called superposition. 

As IBM puts it, “quantum computing harnesses the laws of quantum mechanics to solve problems too complex for classical computers.”² A classical computer has bits that store either a 0 or a 1. In contrast, a quantum computer has qubits that store a 0, a 1, or a 0 and a 1 at the same time. This, along with other quantum properties, enables quantum computers to solve complex problems that would be impossible, or would take way too long, with a classical computer.³

The main body of the conference was of course about using quantum to help achieve Net Zero - but at The PSC we care a lot about space technology, so the first thing I asked him was: 

Would quantum work better in space?

Surprisingly, the answer might be yes. Quantum systems are famously sensitive - vibrations, heat, and even tiny fluctuations can throw them off. Every quantum device needs to be as vibration-free as possible, something that might actually be easier to achieve in the vacuum of space.

The most precise quantum processors need to operate at below 1 Kelvin⁴ (-272°C) - brrrrr - where there is no vibration even from atoms. Even the coldest regions of space - about 2–3K - are a little warmer than this, due to residual radiation from the Big Bang - and those regions are a long way away! Low Earth Orbit, where most of our satellites are, is a tropical-ish 208K (-68°C) in the shade. But, getting down to 1K is much easier from a lower base - meaning that space potentially is a tractable environment for quantum computing at some stage. 

So, what can quantum computing be used for and how does that help us reach Net Zero? 

A few striking examples where classical computing requires a huge amount of processing power, and thus energy, to solve problems through brute force include:

• Medicine & Drug Discovery: quantum systems can analyse all possible molecular interactions at once, unlocking new drug designs or personalised treatment plans.
• New Materials: By testing countless atomic configurations, quantum models could discover materials with ideal combinations of strength, flexibility, and efficiency—vital for renewable infrastructure and lightweight transport.
• Fluid Dynamics in the Heart: every human heart behaves slightly differently. Quantum modelling could allow personalised 3D-printed valves, tailored to individual patients.
• Protein Unfolding: Building on work like Google’s AlphaFold, quantum could fold and unfold proteins in a fraction of the time—advancing bioengineering and climate science alike.

In all of these, there are key wins over classical computing in terms of the emissions we generate: quantum computing will allow us to deliver huge amounts of compute power at enormously lower energy demand than classical compute methods - once you have found a way to get things down to 1K cheaply of course. 

Another key question I asked was - 

Could Quantum computers read our encrypted messages?

And sadly the answer is: almost definitely. The way that quantum computing has the potential to solve millions of problems simultaneously will certainly break traditional encryption. Some organisations are already harvesting encrypted data today, betting that future quantum computers will one day decrypt it. In response, researchers are developing “post-quantum” algorithms - based on new types of mathematical problems that even quantum machines will struggle to solve. That’s great for future messages encrypted the new way - but all those messages being mean about your colleagues which have been encrypted the old way are highly likely to be vulnerable when quantum computing is scaleable. 

What’s possible today - and what’s still years away

Some forms of quantum are already practical. Quantum sensors - which don’t need ultra-low temperatures - can monitor environmental factors like CO₂ emissions with extreme accuracy. Combined with space-based “Direct to Device” technologies, these could one day track emissions globally without relying on 5G infrastructure, allowing monitoring of the most remote locations in the world.

Quantum computing, on the other hand, remains 5–10 years away from real-scale deployment. Current prototypes must be cooled to near absolute zero, limiting them to research labs and nation-state projects. But when they arrive, they’ll be powerful enough to unlock insights - and yes, decrypt messages - stored today.

Quantum communications - transmitting qubits while maintaining their quantum superposition in transit, and quantum key encryption to encode classical messages⁵ - are even further off. So far, experiments have only 110 bits per second over a 250km fibre in lab conditions⁶ - ie, significantly slower than your current broadband provider. The future may be dazzling, but it’s not quite here yet.

Conclusion

Quantum technologies won’t solve the climate crisis alone -but they could become a powerful ally. And space - cold, and with limitless solar power - might be a good place to have quantum compute. 

Author: Phil Buckley, Digital and Space Director

At The PSC, we help public service organisations navigate technological change to accelerate progress. From AI and automation to quantum innovation, we can work with you to explore how to apply these tools safely, strategically, and for public good. Get in touch with us if you want to find out more. And huge thanks to our special correspondent Dr Malcolm Buckley!

References:

¹ Zoe Kleinman (2025) Will quantum be bigger than AI?

² IBM (retrieved 2025) What is quantum computing?

³ Institute of Physics (retrieved 2025) Quantum mechanics

⁴ Wikipedia (retrieved 2025), Quantum computing

⁵ Wojciech Kozlowski and Stephanie Wehner (2019), Towards large scale quantum networks

⁶ Mirko Pittaluga et al, (2025) Long-distance coherent quantum communications in deployed telecom networks