What is Quantum Computing?
Quantum computing is essentially harnessing and exploiting the amazing laws of the quantum mechanics to process information. A traditional computer uses long strings of “bits”, which encode either a zero or a one, however a quantum computer uses quantum bits or qubits. Which means they have the potential to process exponentially more information compared to classical computers.
The Machine
Shell
When the computer is operational, it is encased in five casings (like the white one shown at the top of the image) which wrap around the machine. These fit inside each other and act as thermal shields, keeping everything super cold and vacuum-sealed inside.
Nerves
The coils in these photon-carrying cables are more than just a decorative finish. They ease the stresses that results from supercooling the interior. Without the coils, the data cables would break.
Skeleton
The gold plates separate the cooling zones. In the first chamber the temperature is just below absolute zero. At the bottom, the chamber plunges to one-hundredth of a kelvin, hundreds of times as cold as outer space.
Heart
Beneath the heat exchangers sits the “mixing chamber”. Which houses different forms of liquid helium, helium-3 and helium-4. Which together through separation and evaporation diffuses the heat.
Brain
The QPU (quantum processing unit) features a gold-plated copper disk with a silicon chip inside that contains the machines brain.
Why is Quantum Different?
Superposition
To make sense out of the notion of superposition, let’s consider the simplest possible system: a two-state system. An ordinary, classical two-state system is like an On/Off switch that is always in one state (On) or another (Off). Yet a two-state quantum system is something else entirely. Of course, whenever you measure its state, you will find that it is indeed either on or off, just like a classical system. But between measurements, a quantum system can be in a superposition of both on and off states at the same time, no matter how counter-intuitive, and even supernatural, this may seem to us.
Generally speaking, physicists maintain that it’s meaningless to talk about a quantum system’s state, such as its spin, prior to measurement. Some even argue that the very act of measuring a quantum system causes it to collapse from a murky state of uncertainty to the value (On or Off, Up or Down) that you measure. Although probably impossible to visualize, there’s no escaping the fact that this mysterious phenomenon is not only real but gives rise to a new dimension of problem-solving power that paves the way for the quantum computer. Keep the idea of superposition in mind. We will come back to how this is used in quantum computing in a bit.
How superposition is even possible is beyond the scope of this article, but trust that it has been proven to be true. If you want to understand what gives rise to superposition then you are going to first need to understand the idea of Wave/Particle Duality.
Entanglement
It is known that once two quantum systems interact with one another, they become hopelessly entangled partners. From then on, the state of one system will give you precise information about the state of the other system, no matter how far the two are from one another. Seriously, the two systems can be light years apart and still give you precise and instantaneous information about each other. Let’s illustrate this with a concrete example as this caused even Einstein to puzzle about how this could be possible. (Einstein famously referred to this phenomenon as “Spooky action at a distance”).
Suppose you have two electrons, A and B. Once you have them interact in just the right way, their spins will automatically get entangled. From then on, if A’s spin is Up, B’s spin will be Down, like two kids on a seesaw, except that this holds true even you take A and B to opposite ends of the Earth (or the galaxy, for that matter). Despite the thousands of miles (or light years) between them, it’s been proven that if you measure A to have spin Up, you will know instantly that B’s spin is Down. But wait: we’ve already learned that these systems don’t have precise values for states such as spin, but rather exist in a murky superposition, prior to measurement. So does our measuring A actually cause B to instantaneously collapse to the opposite value, even when the two are light years apart? If so, then we have yet another problem on our hands, because Einstein taught us that no causal influence, such as a light signal, between two systems can travel faster than the speed of light. So what gives? All told, we honestly don’t know. All we know is that quantum entanglement is real, and that you can leverage it to work wonders.
The qubit
The qubit plays the same role in quantum computing as the bit does in classical computing: its the fundamental unit of information. However, compared to a qubit, a bit is downright boring. Although both bits and qubits generate one of two states (a 0 or a 1) as the outcome of a computation, a qubit can simultaneously be in both 0 and 1 states prior to that outcome. If this sounds like quantum superposition, it is. Qubits are quantum systems par excellence.
Just as conventional computers are built bit by bit with transistors that are either On or Off, quantum computers are built qubit by qubit with electrons in spin-states that are either Up or Down (once measured, of course). And just as transistors in On/Off states are strung together to form the logic gates that perform classical computations in digital computers, electrons in Up/Down spin-states are strung together to form the quantum gates that perform quantum calculations in quantum computers. Yet stringing together individual electrons (while preserving their spin states) is far, far easier said than done.
Quantum Computing in Finance
Imagine being able to make calculations that reveal dynamic arbitrage possibilities that competitors are unable to see. Beyond that, greater compliance, employing behavioral data to enhance customer engagement, and faster reaction to market volatility are some of the specific benefits we expect quantum computing to deliver
