The Potential of Quantum Computing
Scientists have recently proposed a new piece of technology which will make creating quantum computers easier. The technology in question is a new kind of qubit, a subatomic particle forming part of a computer system. Quantum computers, the next step in computer technology, use quantum phenomena to perform computations. A current digital computer uses electricity as a binary code with discrete values (on and off). Because quantum particles can exist in a superposition of states (both on and off) with different degrees of probability, quantum computers are theoretically able to perform tasks which normal computers can’t feasibly perform.
Quantum particles appear to be able to exist in multiple mutually exclusive states at once. Unless observed, particles can act as waves rather than discrete objects, existing simultaneously in many places at once. This means that quantum computers can perform different functions with the same qubits. So multiple solutions to a problem can be tried at once, with calculations being made simultaneously rather than sequentially. Quantum computers would be much more powerful than today’s processors, so much so that it could that underpins online transactions such as banking, solving codes that would otherwise require years of work. A 30-qubit computer would have around the same processing power of a conventional computer with billions of bits of memory storage.
Entanglement is another quantum phenomenon that goes beyond our everyday understanding and which could be utilised by quantum computers. Real-world technology exists which is based on the ability for entangled particles to influence each other’s states at a distance. If two quantum computers existed at opposite ends of the planet, containing particles which were entangled, then the processes of one computer could influence the other. Much like computers can connect via the internet, except for quantum computers the connection is direct and unmediated.
That these two phenomena exist in unison just so happens to matter for the feasibility of quantum computing technology. As I’ve said, many people worry about the processing power of quantum superposition being used to break online encryption. But entanglement offers the potential for a more secure form of encryption. Using entanglement, two people could send each other a key-code using entangled particles, to produce a key that only they know. Because of the effect of observation on quantum states, if someone tries to spy on the message, the particles will become disentangled and the keys will be different. Security is ensured by the fact that observation will break the connection between the two computers.
Currently, the science behind quantum computing is still theoretical. The main issue is that quantum effects are very short-lived, with energy being lost from systems into the environment. But scientists are in a race to solve these problems, by for example developing supercooled, superconductive qubits. Google, Microsoft and IBM are all competing to make this sci-fi dream a reality, with predictions that it might become viable as early as this year. When quantum computing becomes mainstream, it will undoubtedly be a giant leap forward in technological progress. We can but guess what avenues this new technology will open up, or where it will take us.