Updated: Oct 8
Author: Arpan Dey
So, this article will be a simple one. I will just make you understand the basic - I mean, the very basic - idea about what quantum computing is all about. This is a topic in which interest has arisen a lot recently. (So, it is likely you won't learn anything new from this article.) I attended a webinar on quantum computing hosted by the New York Academy of Sciences and studied a bit about quantum computing after that. Prior to that, although I studied quantum mechanics in-depth, I largely ignored quantum computing. Well, I am more drawn toward the theoretical and mathematical aspects, rather than the applications. But that is no reason to ignore this revolutionary technology.
Superconductors are used in building quantum computers. Recently, interest in quantum computing has risen and many companies are investing huge sums of money in this technology. Quantum computing is basically a new way to store and process information based on the principles of quantum mechanics. Classical computers store information in binary ‘bits’: 0s or 1s; but quantum computers store information in ‘qubits’ (quantum bits). A qubit can be both 0 and 1 at the same time, and a series of qubits together remember many different things simultaneously. With the advancement of quantum computing technology, it is expected that the size of these computers will decrease and they will be able to function efficiently at room temperatures.
To build a quantum computer, you need to get the system in a superposition state. You can do this in a number of ways. In superconducting loops, a resistance-free current oscillates around a circuit loop and a microwave signal excites the current into superposition states. You can also trap an ion and excite it into a superposition state. You can manipulate the quantum state of an electron, etc.. There are a number of technologies like silicon quantum dots, topological qubits, etc..
It should be noted that quantum computers are highly sensitive and surrounding noises can break the superposition state and disrupt the functioning of the computer. Charges, fields, vibrations, cosmic rays etc.. are the sources of noise. You need to either reduce noise or make the computer insensitive to noise or maintain active quantum error correction. Thus, we see that quantum mechanics is not just theory, it has wide-ranging applications. The principles of quantum mechanics are used in the electronics industry, quantum computing etc..