Quantum computers serve as an alternative tool to replace classical computers. A classical computer performs operations using classical bits, which can either be one or zero. In contrast, a quantum computer uses quantum bits, where one and zero can be present simultaneously. This is what gives a quantum computer superiority over computing power.
Quantum computing is the use of quantum phenomena, such as superposition and entanglement, to perform computation. It seems like an extremely complex sentence, but essentially, it’s simple!
Quantum bits can be a single photon, a nucleus or an electron. All electrons have a magnetic field, so they are similar to tiny magnets. This property allows them to spin; if you place them in a magnetic field they will align with that field, just like an ordinary compass. This is the lowest energy state, which you could call the zero state or spin down (for the electron). Now you can put it in one state or spin up but that takes energy. Right now, we have created something similar to the classical bit, spin up or spin down or 1 and 0. But the amusing thing about quantum objects is that they can be in both states at the same time. When you measure the spin, it will be either up or down but before you measure it the electron can exist in what’s called a quantum super position. This is a where (in a quantum system) it exists in several separate quantum states at the same time. For example, a coin facing up has a definite value; heads up or tails down. Without looking at the coin you can believe it is head or tails. In quantum experience, material properties of things do not exist until they are measured. Until you look, or measure the particular property of the coin, the coin is on its side, it’s neither up nor down.
Quantum entanglement is where the quantum states of two or more objects are contrasted even though the individual objects may be spatially separated. In this quantum mechanical phenomenon, it is possible to have two particles in a single quantum state, so that when one is observed to be spin-up, the other one will be observed to be spin-down and vice versa indefinitely. Despite it being impossible to predict, in accordance with quantum mechanics, this set of measurements will be observed. As a result of this, measurements performed on one will directly influence the other systems entangled with it. However, quantum entanglement does not enable the transmission of classical information faster than the speed of light. Quantum entanglement has been used in the emerging technologies of quantum computing and quantum cryptography, to explore quantum teleportation experimentally.
Quantum Computers can change data security using practically unbreakable encryption. Although quantum computers are able to crack many of today’s encryption methods, predictions suggest that that they will be able to create hack-proof replacements, redefining data security. Quantum computers are excellent tools to solve optimisation problems, for example to figure out the best way to schedule flights at an airport, or to configure the best routes for a delivery truck. These computers work faster than classical computers; Google has announced it has a quantum computer that processes 100 million times faster than any classical computer in its lab. Quantum computers will make it possible to process the massive amount of data we are now generating in the age of big data.
In times of climate change and global warming, the careful use of electricity has become very significant. Rather than consuming more electricity, quantum computers will reduce power consumption anywhere from 100 up to 1000 time by using quantum tunnelling. The quantum tunnelling effect arises when particles that move through a barrier, which disaccords with the theories of classical physics, hence should be impossible to move through. This quantum phenomenon would imply that there is a finite probability that some of the particles will tunnel through the barrier.
Once a stable quantum computer is created, you can expect that machine learning will exponentially accelerate, hence reducing the time to solve problems from hundreds of thousands of years to merely seconds and potentially accelerating the rate of growth of our economy exponentially!