You might have heard of the topic quantum mechanics before, but haven’t really gone over what it is about or which elements it deals with.
Today, we’re going to delve into the basics of quantum mechanics and how the recent quantum computer-Willow – by Google incorporates this.
Put simply, Quantum mechanics is a study of how particles which are of or smaller than atoms behave, where Quantum is a fundamental unit, often the smallest discrete unit of a phenomena. For example, a quantum of electricity is an electron, and a quantum of light is a photon.
Recently, Google invented a quantum computer, which is made based on quantum mechanics.
The main theories of quantum mechanics used to create this computer are quantum superposition and quantum entanglement.
Have you heard of the thought experiment ‘Schrodinger’s cat’?
For those who haven’t heard of this, Schrodinger’s cat is a famous imaginary experiment that deals with quantum superposition. To briefly explain the experiment, Schrodinger proposes a certain situation, where a cat is locked up inside a box with a radioactive substance.
He suggests that this radioactive substance has a certain chance of getting destroyed, and emitting poisonous substance into the box after being broken.
In the case that the radioactive substance is broken, the cat is killed as it is exposed to the poisonous substance, and on the other hand, if the substance isn’t destroyed, the cat will live as the poison is not emitted.
Quantum mechanics suggests that there is no way of determining if the radioactive substance is destroyed before opening the box and observing it.
Hence, given that the chance of the substance getting destroyed is 50%, before observing the outcome in the box, the cat is in its superposition state, where it is considered to be both alive and dead.
Quantum entanglement is a phenomena where two particles that are far apart are linked, and influences each other’s actions. Therefore, it can be assumed that a change in one particle immediately influences the linked particle’s actions.
This phenomenon can occur no matter how far apart the two particles are, as there is no information transmission between these two particles.
These two theorems are used to create Quantum bits, also called Qubits in its shortened form.
Bits, binary digits, either possess a value of 0 or 1, which can be also represented as simple states such as on/off, true/false and so on.
On the other hand, Qubits possesses a value of 0 and 1 at the same time.
If two or more of these ‘Qubits’ are in the entanglement state, when the value of one Qubit is determined, the values of other Qubits linked with it are also determined.
These ‘Qubits’ are what makes Quantum computers like Willow so special.
Qubits allow Quantum computers to perform every route (possibilities) for a calculation in one go, which shortens the time taken.
In a recent publication of a science report called ‘Nature’, Google proposed that the recent quantum computer had managed to calculate a complicated calculation in less than five minutes, which would have taken other super computers ten septillion years- which is 10 to the power of 25 years.
Furthermore, Google also proposed a way of tackling calculation errors called AlphaQubits, which allegedly detects and fixes errors so there are less mistakes in calculations.
Google suggests that they will incorporate Willow to tackle problems that other supercomputers haven’t managed to solve before, and will present this to the public next year. However, no-one yet knows whether Willow will be an invention which moves the pace of science forwards, or a second superconductor which everyone claims to have created, but none of which is known to be made. So we’ll have to hold on tight, while the supercomputer is in its superposition state- between being an innovation like none others, or simply, not as effective as proposed.
