Quantum computing is in your corporate future. And it will provide a competitive advantage. The last fifty years have been the digital era. Digital technology has reshaped the way we live, work and play. But the rate of change in digital technology is notably slowing down, and it becomes a mature and stable technology. So, the smart eyes — and money — are looking towards the next wave of technology: quantum computing. And yes, it could be a revolution as big as digital.

Here’s what you need to know.

What’s quantum computing, then?

Quantum computers use the principles of quantum mechanics to perform computing tasks in a very different way from digital computers. Our existing computing paradigm is based on binary because bits can either hold a 1 or a 0: they can only be in one of two states. Quantum computing allows qubits — their equivalent of bits — to be in any one of multiple states, and to hold a superposition of all possible states. They hold possibility as much as a result. A qubit could be thought of as a die that’s still rolling, while a bit is the result of a coin toss recorded.

Qubits also influence each other through a process called quantum entanglement. And the likelihood of the eventual collapse of superposition into a final value can be influenced by a process called quantum interference.

The core reason we’re interested in all of this, is that it allows quantum computers to solve complex problems that are much more complex than those that can be solved via digital computing.

I’ve heard about quantum supremacy. What’s that then?

Quantum supremacy is achieved when a quantum computer solves a problem that a traditional digital computer couldn’t solve on any realistic timescale. It’s been achieved. And more than once:

A quantum computer made by researchers in China has solved a calculation in 4.2 hours that would take a classical computer thousands of years.

This matters because it means that quantum computing has reached the point where it could start having real-world applications.

What does quantum computing change?

Well, there’s good news and bad news. The bad news is that quantum computing can crack existing encryption methods rapidly. We’re going to need a whole new encryption method:

If they reach their full scale, quantum computers would crack current encryption algorithms exponentially faster than even the best non-quantum machines can. “A real quantum computer would be extremely dangerous,” says Eric Rescorla, chief technology officer of the Firefox browser team at Mozilla in San Francisco, California.

On the more positive side, they have many advantages:

• They can solve complex problems: while digital computers struggle with problems that involve multiple variables — like much of the real world, in fact — quantum computers excel at solving these issues.
• They’re great at simulating systems: the world is a mass of complex, interlocking systems. Quantum computers will allow us to simulate much more complex real-world systems, and thus make better-informed decisions. For example, they’re great at supply chain optimisation.
• They’re really fast: you might think your fancy new M2-powered Mac is fast, but you ain’t seen nothing yet. Quantum computers will be exponentially faster than digital ones.
  

Are there any other downsides?

Well, yes, there are a couple:

• Right now, quantum computers are massive — because of the way they’re built. Let’s come back to that.
• They’re also much more error-prone than digital computers. A process called decoherence means that some external factors can make them inclined to produce “noise” in their results. AI might well prove a solution to this.
  

Wow, I’m looking forwards to having a quantum phone

Uh, you could be waiting a while for that. The actual working parts of the computer are not that far from a desktop PC. The problem? You need to supercool them. And that equipment needed to do that is big. I don’t know about you, but my pocket isn’t a cool place. We’ll need a radical shift in either the way we do quantum computing or the way we cool things before we’ll have a quantum iPhone.

Is it impossible? Far from it. Work is already underway bringing a more manageable size of quantum computer:

Quantum Brilliance is developing quantum computers based on synthetic diamonds, which don’t need temperatures close to absolute zero or complex laser systems to operate. It is in stark contrast to the superconducting quantum systems developed by big companies like Google, IBM and Rigetti which need large and energy-hungry cooling systems to keep them at a temperature colder than interstellar space.

It’s got them down to lunchbox size. Given that it took decades to go from room-sized digital computers to pocket-sized ones, the rate of change is impressive.

In short: Quantum Computing

Quantum Computing will change the way we analyse and interact with complex systems — like ecosystems or markets. You’re unlikely to be buying one for the office any time soon, but you can use them as a cloud platform. They’re great for running simulations of complex systems, but the skills needed to accurately build those systems are still rare. Businesses that are dealing with complex systems or large data sets are finding that it delivers a competitive advantage.

Photo by Laura Ockel on Unsplash.