Quantum supremacy and what it means

Chinese researchers were recently able to confirm Quantum Supremacy. Do you know what it is? Other than a really badass name, it is also the name given to the theory that quantum computing is incredibly more powerful than regular binary computing, such that it is able to complete in a reasonable time a task that even the most powerful computers we have would take millennia to do.

They took a new approach to quantum computing, manipulating photons (that is, particles of light), instead of relying on superconductors (as they need to be kept super frozen). The computer they created, the Jiuzhang, was able to complete in just a few minutes something which the Fugaku, which is currently the fastest supercomputer in the world, would take 600 million years to solve.

This beats Google’s previous record, which used superconductors to calculate in about 200 seconds what a million-core supercomputer would need 10,000 years to calculate. For comparison, the Fugaku has about 800,000 cores.

So, what does this mean?

Approaching quantum computing

Yes, it means we are getting closer to getting a full-blown quantum computer. Even though those results were amazing, they all came from prototypes. We still do not have anything completely usable, much less for domestic use.

Quantum computing will probably follow the evolution of its binary counterpart: it will start as a substitute for quantum computers, used by researchers and companies to do very complex calculations, such as astronomical and meteorological simulations, and will become progressively smaller, entering big companies, server farms, and finally small companies and people’s homes. Doing all that may take some time.

The main challenge is reaching high-fidelity computations. We still haven’t quite got the hang of quantum mechanics, much less the technology to handle it properly and precisely, so the algorithms that exploit the superposition of qubits (that is, quantum bits) can sometimes not generate the correct results. It is a very delicate and difficult process.

With increasing research on both technology (that is, creating better equipment) and theory (creating fault-tolerant algorithms), that will be overcome in the near future.

Solving very difficult problems

With breakthroughs like this one, it seems that the “P=NP” discussion may stop being relevant. This is a theory from computer science that problems that are very hard to solve (such as figuring out a path to place) may actually have a much more straightforward algorithm to solve them.

With quantum computing, a problem would need to be impossibly big for it to be impossible to solve within our lifetime. Algorithm optimization may well becoming a thing of the past, unless our computation needs become exponentially greater with time. But just the same, science and technology will advance at a exponentially faster pace thanks to it, so they may very well be able to keep up.

Cryptography

But, not all good news are entirely good. If you are putting your hopes on current cryptocurrencies, it is a good idea to keep an eye out for when quantum computers become a reality.

Even though quantum cryptography is theorized to be virtually unbreakable (thanks to quantum tricks such as superposition), all of the current cryptography technology relies on the fact that current computers would take centuries to break them. Meanwhile, for quantum computer they are a piece of cake. So, we may end up with a “crypto-bubble” as internet security technologies adapt to this new computing technology. Hopefully a transitioning strategy will be put in place to prevent people from exploiting it.

However, current cryptocurrencies will have a hard time. As they are independent initiatives, maintained by volunteers, and government agencies aren’t really interested in keeping them alive, they may face problems as people with access to quantum computing become able to break its cryptography and hashing, and mine thousands of coins in seconds.

Just the same, quantum cryptocurrencies will rise from their ashes, and early adopters of the technology will be the first ones to profit from it. And they will prove to be even safer than the current ones. Survival of the fittest, as always.