What is quantum computing?

Or better yet, why is it important?

Let me turn it over to Satya Nadella for this one.

As Nadella puts it: “One fascinating way to think about quantum is that if you had a corn maze and you were trying to trace your path. A classical computer would trace, retrace again and again and on and on. Quantum is the ultimate parallel machine. It would trace all of the paths simultaneously.”

As a race, humans have always strived to make things better, faster, and stronger. And since personal computers became a thing, there have been plenty of optimizations to keep those electrical and computer engineers busy.

However, computers are fast getting to a point where the most impactful limitation on computers is the fundamental architecture of the computer itself.

Let’s dive into this a little bit more.

You can think of a traditional computer architecture as effectively millions of switches. This is a simplified way to look at it, but for the scope of this post, we’ll maintain this analogy.

Each of these switches can be turned on or off. It’s a simple binary. Either the switch is 100% ON AND 0% OFF, or it is 0% OFF AND 100% ON.

That type of architecture (which we will refer to as binary architecture) is pretty good. Really good, in fact. So good, that we have built almost every computer and computer system from the ground up using these switches.

So what is the problem with it?

These metaphorical switches are actually electrical signals. When the switch is on, its electrical signal goes ‘high’. When the switch is off, its electrical signal goes ‘low’. The actual voltages of the switches do not necessarily matter as long as there is a clear boundary between what is considered ‘high’ and ‘low’.

One of the great things about using electrical signals for these switches is that electricity is really fast. And for decades, electricity was fast enough. However, computers have advanced so much that that speed is no longer good enough.

“Ok Quantum Authority, so computers have gotten so good that they are in danger of outpacing the speed at which an electrical signal can switch from ‘high’ to ‘low’ (or vice versa). So the limiting factor is the speed of electricity, right?”

Right.

Can we make the electricity move faster? The short answer is within reason, but ultimately that optimization will not be good enough.

So what else can we do to solve this problem?

Quantum Computers, my friend.

Let’s go back to our switch analogy. We had it such that the switch could be in one of two states:

The switch could be 100% ON AND 0% OFF

Or

The switch could be 0% ON AND 100% OFF

But what if there was a way to make it so that the switch could be partially on and partially off at the same time?

Now our analogy gets a little fuzzy. How can a switch be partially on and partially off? This is the fundamental concept behind quantum computing.

As a discipline, quantum computing is all about defining that space in between on and off and utilizing it to make computers faster.

How much faster? Some say on the order of 100 million times faster (!!!)

How insane is that??

If you’re interested in the more practical applications of such speed, then slide on over to our Applications of Quantum Technology section.

In short, this technology means:

• Better and faster artificial intelligence
• Faster algorithmic trading
• The ability to better hack and defend against hacks.

So now that we understand what quantum computing is at a high level, how does it actually work at a more technical level? Read on to find out.